Hey RadoslawDabrowski - sorry I didn't see this sooner. Notifications had issues
Are you doing this as part of an actual blueprint or are you creating a network to add to a network profile after the fact (provider infrastructure as code usecase). In the latter, it should be creating a Tier-1 router that links up to a Tier-0
Those settings are there for if you have multiple Tier-0 routers, and you want to specify the one to use for a given network profile. If you only have 1 Tier-0, it's "implied" within the profile as that being the one to use.
Can you share your blueprint that you're using here? I can confirm a few things in my environment.