Hi Jay,
Multi-Factor Authentication (MFA) is a two-step verification method of authentication which requires more than one verification method and add additional security layer for users. Your concern of activating it through a user portal is complicated that what is typically answered here in Microsoft Answers Forum and is best suited for our IT Professionals audience in TechNet Forum. Refer to this link to post your query on TechNet Windows 10 IT Pro Forum.
Let us know if you need anything else. We're here to help.