Using Ha-Bridge to control a Domoticz GROUP using the 'Domoticz Tab' to create the device.

It uses the command:
http://IP:8080/json.htm?type=command&param=switchlight&idx=15&switchcmd=On

It should use:
http://IP:8080/json.htm?type=command&param=switchscene&idx=15&switchcmd=On

note 'switchscene' rather than 'switchlight'.

(n.b. Domoticz 'scenes' are correctly constructed using the 'swicthscene' api command)