Oracle cloud free tier MFA failed - urgent!

I cannot login to my cloud account via MFA using the code generated by Oracle Authenticator app. It was still working a couple weeks back. I tried the hack posted in this forum like changing the URL when asked for authentication code, but didn't work.

I cannot find support email I can send to resolve this issue.

If there is no other options, is it possible to upgrade my account to paid account. By doing this, at least I can get someone from support team to look into my account.

Much appreciate if someone could point me to the right direction.