This is a flow which changes the state of a zigbee2mqtt group (of bulbs) with an vritual on/off switch in domoticz. The idx=183 is the domoticz object
[{"id":"56035fe2.21c4e8","type":"tab","label":"Keuken_Licht_Group","disabled":false,"info":""},{"id":"17b6b703.ebe381","type":"mqtt in","z":"56035fe2.21c4e8","name":"","topic":"domoticz/out","qos":"2","datatype":"auto","broker":"b90f182d.2e6838","x":134.50003051757812,"y":210,"wires":[["452631d0.ef45a8"]]},{"id":"52d623f.852d35c","type":"comment","z":"56035fe2.21c4e8","name":"Domoticz Switch for Kitchen Light Group","info":"","x":224.00003051757812,"y":157,"wires":[]},{"id":"452631d0.ef45a8","type":"json","z":"56035fe2.21c4e8","name":"","property":"payload","action":"","pretty":false,"x":288.50006103515625,"y":210,"wires":[["96dc8119.c7418"]]},{"id":"96dc8119.c7418","type":"function","z":"56035fe2.21c4e8","name":"Turn On/Off Z2M Group","func":"if(msg.payload.idx == '183') {\n//if(msg.payload.idx == '268') {\nif(msg.payload.nvalue == '0') {\n msg.payload.state = 'OFF'\n}\nif(msg.payload.nvalue == '1') {\n msg.payload.state = 'ON',\n msg.payload.brightness = 120,\n msg.payload.color_temp = 350\n}\nreturn msg;\n}","outputs":1,"noerr":0,"x":489.7713928222656,"y":210.00000381469727,"wires":[["5eba5b0b.72b304","25b6c7eb.71f88"]]},{"id":"5eba5b0b.72b304","type":"mqtt out","z":"56035fe2.21c4e8","name":"","topic":"zigbee2mqtt/Keuken_Spots/set","qos":"","retain":"","broker":"1ec43ef1.2b0269","x":762.8785705566406,"y":210.37855529785156,"wires":[]},{"id":"25b6c7eb.71f88","type":"debug","z":"56035fe2.21c4e8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":716.2666320800781,"y":323.4499816894531,"wires":[]},{"id":"b90f182d.2e6838","type":"mqtt-broker","z":"","name":"Domoticz","broker":"127.0.0.1","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""},{"id":"1ec43ef1.2b0269","type":"mqtt-broker","z":"","name":"Zigbee2mqtt","broker":"127.0.0.1","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"domoticz/bridge/state","birthQos":"0","birthPayload":"online","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""}]