OK got it to work 
First add to the Execute Command action
miIO.ir_learn {"key": "1"}
The command is automaticaly executed, check the logs. Use Karaf
openhab> log:tail org.openhab.binding.miio
then enter
miIO.ir_read {"key": "1"}
and read the token
then enter
miIO.ir_play {"freq": 38400, "code": "Z6VHADUCAACbBgAAuggAAIIRAABmIwAAQJwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA0AAAAEAAAAAAQEBAAEBAQEAAAAAAQAAAAEBAQEAAQEBBQJAA="}
The IR signal should be sent
Some help here → Add tests for the Chuangmi IR controller · Issue #175 · rytilahti/python-miio · GitHub