webOS Integration commands

Is anybody aware of service endpoint in the webOS API to queue/trigger commands for the universal control feature? I am trying to use the remote of my TV turn turn on our old AV Receiver.

While it is possible to automate this via button presses, this is very unreliable due to timing issues and dynamic menus.

From what I was able to gather to this point the endpoint seems to be
com.webos.service.mrcu/ir/pushIrCodes

Taken from:

I wasn’t yet able to send a successful request to that endpoint.