Simulate shutter position with UP/DOWN/FAVORITE buttons

hello

I have shutters which do not provide the current position.

I would like to simulate them when I action them

  • UP : 0%
  • DOWN : 100%
  • FAVORITE : 50%

I can create an automation but how to add the “position” attribute in the shutter device which is not existing (I’m using OverKiz integration for Somfy shutter)

Thanks