Disable MFA on free version of Teams

It would be worth trying LinusCansby  tip but I wonder if you'll have access with the free version, that's more https://docs.microsoft.com/en-us/microsoftteams/manage-freemium.  

MFA is being enabled across the board using security defaults "we are applying security defaults for all license levels, even trial tenants, ensuring every account can be protected by MFA." - Introducing security defaults.  If you have access, this would be the https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/concept-fundamentals-security-defaults#disabling-security-defaults.