Using open source on premise edition, is there some way to get MFA with LDAP auth? We don't have google work apps.
No, you need to connect MFA to your LDAP solution. If the authentication is managed outside Metabase (in this case an external LDAP server) then the MFA should be done at that level as well. There's a feature request to add MFA to Metabase as well 2FA support request · Issue #3729 · metabase/metabase · GitHub