Try this:
Does the homey app have access to your camera? If so:
First go to the HUE app.
Select settings → smart home → other apps.
Then you get in the matter menu of hue. Select the button to get a code and copy it:
Then go to homey app and add a matter device as you did. At the scan code screen push the scan code button and in the following screen select more options:
The following screen appears:
Select the bridge bringing you to a screen requesting the code.
