Hi pnp marine,
You can use the Account recovery Form (https://account.live.com/acsr) to prove ownership. Provide as much detail as possible (e.g., old passwords, email aliases, security info, purchase receipts for Microsoft services). This is critical if you’re locked out entirely.
You can reach out via phone number based on your country: Global Customer Service phone numbers - Microsoft Support
Please kindly understand that the Outlook tag here we mainly focus on general issues about Outlook desktop client. In order to better solve your problem, it's suggested that you could post your case in dedicated forum for Microsoft Authenticator for more professional advice.
Thanks for your support and understanding!
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