Can’t sign in to admin account – MFA code not delivered to phone (Error Code: 399287)

Hello,

I’m unable to sign in to my Microsoft 365 admin account because the MFA verification code is not being delivered to my phone.

I don’t have any other administrator account in the tenant that could reset my MFA methods, so I’m currently locked out of administration completely.

Could you please advise how to restore access, or how to verify my identity so the MFA methods on this account can be reset? I’m happy to provide any information needed for verification.

Thank you for your help.