If you have already exhausted your account recovery options, made sure your account is correctly configured, and tried logging in using a fresh browser in incognito mode, you may need to reach out to the Azure Data Protection team.
If you are the only global admin on the tenant, the Azure Data Protection team will help you get unlocked. (Otherwise they will ask you to get access from another admin on your tenant.)
Azure Data Protection phone number: (866-807-5850)
Hope this helps!