Wifi calling on iphone

Wifi calling on my iPhone 16 max is not working.

When I try to enable wifi calling I get the message "contact carrier".

I contacted google support: https://support.google.com/fi/gethelp?authuser=0

1. restart phone. test --> same result / "contact carrier"
2. reinstall Google fi. Reboot twice. --> same result
3. try Airplane mode and turn on wifi calling --> same result
4. restart network on iphone Settings > General > Transfer or reset iphone > Reset > Reset Network Settings. --> same result
5. Google rep to check the towers in my neighborhood.
   The rep claims that there is an issue with the towers and I should try rebooting my iphone, try to get wifi calling to work, and try airplane mode.

Net result: 30 minutes of fiddling -- and no wifi calling

UGH!

to contact google support: https://support.google.com/fi/gethelp?authuser=0

*it can be a pain to find that link.