Hi there
Can anyone tell me if it is possible to control the zigbee bulb with a KNX button ?
please help … I’m tearing my hair off

in short yes.

Provided both are connected to Homey and supported.

Hi thanks for your feedback

zigbee is from ikea and my knx button Is also find as I have all my group adresses inside my homey via ip router.

but am in doubt whether homey can communicate both ways from the knx bus both send and receive signals, I can send an on signal on my knx bus from an ikea button, but can not send values and signals from the knx bus out on my homey and on to ikea light sources.

So you have a KNX button but no device in Homey with an “the button is pressed” trigger?

Imho you don’t have a supported Homey KNX device then.
Get the button supported in Homey…
that is as always the way to go.