Docker, build your custom image, entry point in error

General
5

I admit that I don't immediately understand why you are getting that error.
I have checked that folder for my container and it contains red.js:

bash-5.0$ pwd
/usr/src/node-red/node_modules/node-red
bash-5.0$ ls
CHANGELOG.md  LICENSE       README.md     bin           lib           package.json  red.js        settings.js
bash-5.0$

... but I noted that my package.json doesn't contain the start command.

So here a copy of my package.json (I have removed 2 dependencies from it).

{
    "name": "node-red-mydrive-ctrl",
    "description": "Node-RED My-Drive Controller",
    "version": "0.0.1",
    "dependencies": {
        "node-red-node-daemon": "0.2.1",
        "node-red-dashboard": "2.29.0"
    },
    "node-red": {
        "settings": {
            "flowFile": "flows.json",
            "credentialsFile": "flows_cred.json"
        }
    }
}

So can you update your package.json to make it more like mine (or test in the first place with my package.json) and check if that not fixes the problem ?