Authorization failed or requested resource not found.

I have a free tier account, and it works well in the last one year. However, my account suddently doesn't work in the one month before.

My default domain: Authorization failed or requested resource not found

My tenancy is inactive, and Audit retention period: You are not authorized to view audit configuration details.

It seems that my account is locked, and I cannot find any ways to unlock it. Please refer to the following sceenshot.