Hello, thank you for reaching out to Microsoft Q&A.
Please note that Microsoft takes account privacy and security very seriously. Therefore, apart from the account owner, no one has permission to view or share your personal identifiable information (PII), such as your email address. In fact, we do not have access to that information here.
In situations like this, where you no longer remember your Outlook email address, please reach out to your friends or neighbors to see if they can help you identify it. If you have ever sent emails from this Outlook account to your friends, you can ask them to check the full email address in their mailbox and share it with you.
Alternatively, if you have been using a password manager in Google Chrome or Microsoft Edge, you can open it and check the saved passwords or accounts. Look for entries related to live.com, outlook.com, or Microsoft accounts to see if your Outlook sign-in details were saved there.
For reference, see
Check products or services where you used your Microsoft account