Hi anonymous user,
It appears that it's no longer possible to link accounts:
https://support.microsoft.com/en-us/account-billing/linking-microsoft-accounts-4044c1bc-f436-60eb-9f6d-2bf64a7cc47f
You can try the following:
- Sign in to your Microsoft account.
- Select Your info > Manage how you sign in to Microsoft > Add email, add a email-address you already have.
More detailed information, please refer to "Change the email address or phone number for your Microsoft account".
You may also try asking for help over here:
https://trainingsupport.microsoft.com/en-us/mcp/forum/mcp_prof-mcp_link
(If the reply was helpful please don't forget to upvote or accept as answer, thank you)
Best regards,
Leon