Can't add billng account

[Floki]

I tried using all the payment methods I had, I tried 2 cards, tried a bank account and a prepaid card, tried deleting and setting up payment methods, and all attempts were pointless, I received errors, different ones, when I tried everything to upgrade the plan in Firebase I got OR-CCSEH-21, and when I tried to connect to Google Cloud functions and get $300 I got OR-CBAT-15.
I can't contact support because it needs a billing account and other support says they can't do anything. How do I add a Billing Account

thanks for the help