Managing personal Outlook.com account settings, security, and privacy
Hey there! Nice to meet you!
Based on your description, there is a possibility that someone is trying to login to your account. Please ignore the verification code request.
Then make sure that the two-step verification feature is still enabled on account.microsoft.com > Security > Turn on two-step verification.
Also, please check that there are no unfamiliar email addresses/phone numbers added to your account's security info on account.microsoft.com > Security > Manage How you Sign in.
Ensure that your account's security info is always updated and that you always have access to it. If there is an unfamiliar email/phone number in your security info, click on Manage, then remove it.
Lastly, follow the guide from this thread to prevent unauthorized logins:
Please feel free to let me know if you need anything else.
Best Regards,
Darhyl