Node Red service node doesn't seem to communicate with home assistant

Sorry. The “Call-service API error …” is not an issue. Turns out that was me jumping the gun on the ‘deploy’. Regarding expansion of the details, the full line is

{“domain”:“switch”,“service”:“turn_on”,“data”:{“entity_id”:“switch.attic_fan”}}

I’m not sure if that is what you meant.

Is it working now that you deployed then? Because that debug data looks right so if its still not working I’m not sure what other help I can give here. Hopefully someone else has some ideas.

Sorry for the late response but the system time limits the number of responses a new user can submit but Yes!! Somewhere in the combination of multiple variables we’ve changed, it started working (not least of which was actually deploying).

Many thanks!

For the record, here is the final working configuration: