Hi,
If this account has not been used in the past four or five years, I’m sorry to say that it is no longer recoverable. Microsoft automatically closes accounts that have been inactive for two years, and in such cases, the account recovery form will no longer work.
Microsoft explained that here: https://support.microsoft.com/topic/microsoft-account-activity-policy-7c0a9fa7-0982-b7c6-fd72-df852b63699f