From my experience, it's really hard to create an account and upgrade your account to PAYG. People saying you need that if you want to get the free tier VM because the free tier VM keep out of stock.
I need to email the customer support to make an account and even then to change my account to PAYG account, I need to register the credit card again, they keep rejecting my credit card even though that is the same credit card that I used for my account and the test payment go through.
After that I just give up and go with Hetzner (same you need to email CS) but I can start paying them immediately after the account created.
I had a different experience. I upgraded a free account last year without needing email anyone. And only did that to use some non-free feature. I had no problems creating free tier compute instances but maybe it depends on region, I'm in Ashburn.
Same I'm on a paid account, currently running a Kubernetes cluster for free is Phoenix. No issues converting from the free account and only once wasn't able to provision one of the ARM vms, and just provisioning in a different AZ worked.
I need to email the customer support to make an account and even then to change my account to PAYG account, I need to register the credit card again, they keep rejecting my credit card even though that is the same credit card that I used for my account and the test payment go through.
After that I just give up and go with Hetzner (same you need to email CS) but I can start paying them immediately after the account created.