If two-step verification is enabled on the Microsoft account, for security reasons, Microsoft support cannot bypass or “override” two-step verification if you no longer have access to the verification methods.
What you can do is try to regain access using any previously trusted/signed-in device (PC, phone, Xbox, browser session) and then update security info from the account’s Security settings once you’re in.
If you had generated a Microsoft account recovery code earlier, that can also restore access, but it must have been created before you were locked out. If none of the verification methods are available and you don’t have a trusted device/session, then realistically there isn’t a supported path to recover that account, at that point you’d need to create a new account and secure it with multiple backup methods going forward.