How to sign into Apple ID with two factor code when all devices are signed out?

One Mac, One iPhone. Both were signed out of Apple ID. When I try to sign in the Mac, it wants the two factor code, which I can't get with the phone because it was signed out. When I try to manually get a two factor code from iPhone it asks me to sign into apple id, and it too wants to send a code.

I'm stuck in a loop. What to do?

The phone can't get a cell signal, so that's ruled out. I have wifi available, that's it.