"TypeError: Cannot read properties of undefined (reading )"

I am new user of Node red and I am working on a project to show random question on dashboard.
The user answers by pushing on one of the presented button (True / False) presented on dashborad.
When simulating the flow, I have an error : "TypeError: Cannot read properties of undefined (reading 'reponse )".
Could you help me to find the problem.
Thank you in advance.
Here you will find the code.

[
    {
        "id": "343e552e8fc04ec0",
        "type": "tab",
        "label": "Flow 4",
        "disabled": false,
        "info": "",
        "env": [ ]
    },
    {
        "id": "78234bc16c766e6a",
        "type": "inject",
        "z": "343e552e8fc04ec0",
        "name": "Départ quiz",
        "props": [
            {
                "p": "payload"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 230,
        "y": 120,
        "wires": [
            [
                "a177a810816289f2"
            ]
        ]
    },
    {
        "id": "a177a810816289f2",
        "type": "function",
        "z": "343e552e8fc04ec0",
        "name": "Générer question",
        "func": "const questions = [\n    {\n        question: \"La première révolution industrielle a introduit l'utilisation de la vapeur et des machines à vapeur. Vrai ou faux ?\",\n        reponse: true\n    },\n    {\n        question: \"La deuxième révolution industrielle était caractérisée par l'utilisation de l'électricité et des chaînes de montage. Vrai ou faux ?\",\n        reponse: true\n    },\n    {\n        question: \"La troisième révolution industrielle est souvent appelée \\\"révolution numérique\\\" ou \\\"révolution informatique\\\". Vrai ou faux ?\",\n        reponse: true\n    },\n    {\n        question: \"La quatrième révolution industrielle est caractérisée par l'intégration de technologies numériques, biologiques et physiques. Vrai ou faux ?\",\n        reponse: true\n    }\n];\n\n// Sélectionner aléatoirement une question\nconst questionAleatoire = questions[Math.floor(Math.random() * questions.length)];\n\n// Envoyer la question\nmsg.question = questionAleatoire;\nmsg.payload = questionAleatoire.question;\n//msg.payload = msg.question.reponse;\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 510,
        "y": 120,
        "wires": [
            [
                "51c4338cc5116254",
                "eecbd22fdf0c1027"
            ]
        ]
    },
    {
        "id": "51c4338cc5116254",
        "type": "ui_text",
        "z": "343e552e8fc04ec0",
        "group": "c7152d4603350716",
        "order": 1,
        "width": 18,
        "height": 2,
        "name": "",
        "label": "Question",
        "format": "{{msg.payload}}",
        "layout": "col-center",
        "className": "",
        "style": "",
        "font": "",
        "fontSize": "",
        "color": "#000000",
        "x": 800,
        "y": 120,
        "wires": []
    },
    {
        "id": "675199f3b64efb40",
        "type": "ui_button",
        "z": "343e552e8fc04ec0",
        "name": "Vrai",
        "group": "c7152d4603350716",
        "order": 4,
        "width": 3,
        "height": 1,
        "passthru": false,
        "label": "Vrai",
        "tooltip": "",
        "color": "",
        "bgcolor": "",
        "className": "",
        "icon": "",
        "payload": "true",
        "payloadType": "bool",
        "topic": "",
        "topicType": "str",
        "x": 150,
        "y": 240,
        "wires": [
            [
                "1e851fe0b5cfb5df"
            ]
        ]
    },
    {
        "id": "14504d4c6029deef",
        "type": "function",
        "z": "343e552e8fc04ec0",
        "name": "Vérifier réponse",
        "func": "const reponseUtilisateur = msg.payload;\nconst reponseAttendue = msg.question.reponse;\n\nif (reponseUtilisateur === reponseAttendue) {\n    msg.payload = \"Correct !\";\n} else {\n    msg.payload = \"Incorrect.\";\n}\n\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 560,
        "y": 300,
        "wires": [
            [
                "33139767b681cd82",
                "3978b4a960fdb2ab"
            ]
        ]
    },
    {
        "id": "33139767b681cd82",
        "type": "ui_text",
        "z": "343e552e8fc04ec0",
        "group": "c7152d4603350716",
        "order": 10,
        "width": 6,
        "height": 1,
        "name": "Résultat",
        "label": "",
        "format": "{{msg.payload}}",
        "layout": "row-spread",
        "className": "",
        "style": "",
        "x": 760,
        "y": 220,
        "wires": []
    },
    {
        "id": "937eeb5907498e47",
        "type": "ui_button",
        "z": "343e552e8fc04ec0",
        "name": "Faux",
        "group": "c7152d4603350716",
        "order": 6,
        "width": 3,
        "height": 1,
        "passthru": false,
        "label": "Faux",
        "tooltip": "",
        "color": "",
        "bgcolor": "",
        "className": "",
        "icon": "",
        "payload": "false",
        "payloadType": "bool",
        "topic": "",
        "topicType": "str",
        "x": 150,
        "y": 300,
        "wires": [
            [
                "1e851fe0b5cfb5df"
            ]
        ]
    },
    {
        "id": "3978b4a960fdb2ab",
        "type": "debug",
        "z": "343e552e8fc04ec0",
        "name": "Réponse utilisateur",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "true",
        "targetType": "full",
        "statusVal": "",
        "statusType": "auto",
        "x": 830,
        "y": 360,
        "wires": []
    },
    {
        "id": "eecbd22fdf0c1027",
        "type": "debug",
        "z": "343e552e8fc04ec0",
        "name": "debug 1",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "true",
        "targetType": "full",
        "statusVal": "",
        "statusType": "auto",
        "x": 700,
        "y": 40,
        "wires": []
    },
    {
        "id": "1e851fe0b5cfb5df",
        "type": "function",
        "z": "343e552e8fc04ec0",
        "name": "function 1",
        "func": "// Vérifier si msg.question existe et possède la propriété 'reponse'\n\n\nif (msg.question && typeof msg.question === 'object' && msg.question.hasOwnProperty('reponse')) {\n    // Votre logique pour vérifier la réponse\n    const reponseUtilisateur = msg.payload;\n    const reponseAttendue = msg.question.reponse;\n    \n\n    if (reponseUtilisateur === reponseAttendue) {\n        msg.payload = \"Correct !\";\n    } else {\n        msg.payload = \"Incorrect.\";\n    }\n} else {\n    // Cas où msg.question est indéfini ou ne possède pas la propriété 'reponse'\n    msg.payload = \"Erreur : Données de question manquantes.\";\n    const reponseUtilisateur = msg.payload;\n    msg.payload = \"valeur utilisateur\";\n    msg.payload = reponseUtilisateur;\n}\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 340,
        "y": 260,
        "wires": [
            [
                "14504d4c6029deef"
            ]
        ]
    },
    {
        "id": "6e3306b717982d13",
        "type": "ui_spacer",
        "z": "343e552e8fc04ec0",
        "name": "spacer",
        "group": "c7152d4603350716",
        "order": 2,
        "width": 18,
        "height": 1
    },
    {
        "id": "d31d6539a9186b54",
        "type": "ui_spacer",
        "z": "343e552e8fc04ec0",
        "name": "spacer",
        "group": "c7152d4603350716",
        "order": 3,
        "width": 1,
        "height": 1
    },
    {
        "id": "4caccfd7166af9c1",
        "type": "ui_spacer",
        "z": "343e552e8fc04ec0",
        "name": "spacer",
        "group": "c7152d4603350716",
        "order": 5,
        "width": 10,
        "height": 1
    },
    {
        "id": "3f35559fb7f6ea2c",
        "type": "ui_spacer",
        "z": "343e552e8fc04ec0",
        "name": "spacer",
        "group": "c7152d4603350716",
        "order": 7,
        "width": 1,
        "height": 1
    },
    {
        "id": "f298411fa2a5f24d",
        "type": "ui_spacer",
        "z": "343e552e8fc04ec0",
        "name": "spacer",
        "group": "c7152d4603350716",
        "order": 8,
        "width": 18,
        "height": 1
    },
    {
        "id": "a925aeb749633fbd",
        "type": "ui_spacer",
        "z": "343e552e8fc04ec0",
        "name": "spacer",
        "group": "c7152d4603350716",
        "order": 9,
        "width": 7,
        "height": 1
    },
    {
        "id": "d76a746cb151199e",
        "type": "ui_spacer",
        "z": "343e552e8fc04ec0",
        "name": "spacer",
        "group": "c7152d4603350716",
        "order": 11,
        "width": 5,
        "height": 1
    },
    {
        "id": "c7152d4603350716",
        "type": "ui_group",
        "name": "Default",
        "tab": "95e6a5b444895807",
        "order": 1,
        "disp": true,
        "width": 18,
        "collapse": false,
        "className": ""
    },
    {
        "id": "95e6a5b444895807",
        "type": "ui_tab",
        "name": "Chef d'oeuvre",
        "icon": "dashboard",
        "disabled": false,
        "hidden": false
    }
]

We cannot use your code like that @Ouss.

Please edit your post and put one line above, one line below the code with three back ticks in.
Like this:
image

OK, it's done. Thanks.

Messages on one wire are not available other wires, so your other functions do not see them, so you get errors of undefined.
You would need to join the messages , then you can compare.
e.g.

[{"id":"78234bc16c766e6a","type":"inject","z":"343e552e8fc04ec0","name":"Départ quiz","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":110,"y":120,"wires":[["a177a810816289f2"]]},{"id":"a177a810816289f2","type":"function","z":"343e552e8fc04ec0","name":"Générer question","func":"const questions = [\n    {\n        question: \"La première révolution industrielle a introduit l'utilisation de la vapeur et des machines à vapeur. Vrai ou faux ?\",\n        reponse: true\n    },\n    {\n        question: \"La deuxième révolution industrielle était caractérisée par l'utilisation de l'électricité et des chaînes de montage. Vrai ou faux ?\",\n        reponse: true\n    },\n    {\n        question: \"La troisième révolution industrielle est souvent appelée \\\"révolution numérique\\\" ou \\\"révolution informatique\\\". Vrai ou faux ?\",\n        reponse: true\n    },\n    {\n        question: \"La quatrième révolution industrielle est caractérisée par l'intégration de technologies numériques, biologiques et physiques. Vrai ou faux ?\",\n        reponse: true\n    }\n];\n\n// Sélectionner aléatoirement une question\nconst questionAleatoire = questions[Math.floor(Math.random() * questions.length)];\n\n// Envoyer la question\n\nmsg.payload = questionAleatoire;\nmsg.topic = \"question\";\n//msg.payload = msg.question.reponse;\nreturn msg;","outputs":1,"timeout":"","noerr":0,"initialize":"","finalize":"","libs":[],"x":370,"y":120,"wires":[["fb18dd3a7e667099"]]},{"id":"fb18dd3a7e667099","type":"join","z":"343e552e8fc04ec0","name":"","mode":"custom","build":"object","property":"payload","propertyType":"msg","key":"topic","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"","count":"2","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":310,"y":180,"wires":[["eecbd22fdf0c1027","be97bfa00b78d1aa"]]},{"id":"25d62af06f0658b0","type":"inject","z":"343e552e8fc04ec0","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"response","payload":"true","payloadType":"bool","x":130,"y":200,"wires":[["fb18dd3a7e667099"]]},{"id":"e2e6f19f779ccb87","type":"inject","z":"343e552e8fc04ec0","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"response","payload":"false","payloadType":"bool","x":140,"y":240,"wires":[["fb18dd3a7e667099"]]},{"id":"eecbd22fdf0c1027","type":"debug","z":"343e552e8fc04ec0","name":"debug 1","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":560,"y":100,"wires":[]},{"id":"be97bfa00b78d1aa","type":"switch","z":"343e552e8fc04ec0","name":"","property":"topic","propertyType":"msg","rules":[{"t":"eq","v":"response","vt":"str"}],"checkall":"true","repair":false,"outputs":1,"x":470,"y":180,"wires":[["1e851fe0b5cfb5df"]]},{"id":"1e851fe0b5cfb5df","type":"function","z":"343e552e8fc04ec0","name":"function 1","func":"// Vérifier si msg.question existe et possède la propriété 'reponse'\n\n\nif (msg.payload.question) {\n    // Votre logique pour vérifier la réponse\n    const reponseUtilisateur = msg.payload.response;\n    const reponseAttendue = msg.payload.question.reponse;\n    \n\n    if (reponseUtilisateur === reponseAttendue) {\n        msg.payload.answer = \"Correct !\";\n    } else {\n        msg.payload.answer = \"Incorrect.\";\n    }\n} else {\n    // Cas où msg.question est indéfini ou ne possède pas la propriété 'reponse'\n    msg.payload = \"Erreur : Données de question manquantes.\";\n    const reponseUtilisateur = msg.payload;\n    msg.payload = \"valeur utilisateur\";\n    msg.payload = reponseUtilisateur;\n}\nreturn msg;","outputs":1,"timeout":"","noerr":0,"initialize":"","finalize":"","libs":[],"x":500,"y":220,"wires":[["3978b4a960fdb2ab"]]},{"id":"3978b4a960fdb2ab","type":"debug","z":"343e552e8fc04ec0","name":"Réponse utilisateur","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":790,"y":280,"wires":[]}]

Specifically: in "Vérifier réponse" there is no msg.question so trying to access msg.question.response gives the error.

Thank you !