Doesn't matter. Just go ahead with the settings
Once the settings is completed, you will see a slightly different GUI

In there, do this:
1. Go to LAN
2. Go to IPTV
3. Choose UniFi Home

Submit, then the router will be able to connect to UniFi

Oh, next time you have an issue with ASUS router, go to the ASUS support thread instead of creating a new thread
Here: https://forum.lowyat.net/topic/2651405