Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Can you sign into your personal account via this link: https://account.live.com?
If so, go to Your Info > Sign in preference, Add an alias.
Create new: this will allow you to use the native domain outlook.com to create a new alias.
Once added, make this new alias your primary alias, then you can delete the other email as alias or keep it. It’s up to you. but all your purchased products won’t be affected.