Just want to add that the remote is actually not needed to add a bulb.
I just bought a gateway and two bulb’s, and when I tried to set it up in the app it kept asking for a remote.
I thought bummer! But when I was about to pack it all away I just saw the pairing button ON THE GATEWAY!
Pushing that for 10 secs close to a bulb seemed to do the trick, the zigbee link LED stopped flashing and turned solid.
The app still asked me to add a remote, but in OpenHAB I was able to see, and control, the bulb!
The IKEA app is still useless (asking to add a remote) but OpenHAB is fully functional, I can control both brightness and color temperature.