Account duplication

Dear

I received mail-notifications of new badges earned on my account (linked to my professional email) and when I click the link to see them, I can view my profile as others would see it: I saw my badges, my posts, ...

However, when I log in (with the same account that received the notification), I had to set up a new account (it asked to create a username and in the settings I could see it was newly created). I even tried to log into my personal account (as these are linked for my Microsoft Learn certifications), but then I was also asked to set up a new account.

-> How can get into my original account, instead of the duplicates that were created on the same e-mailadres?