Restrict login to ANM app best practices

Hi, I have an ANM project published on a public website (based on IIS).
My client ask me a more robust authentication method, not only username and password.
I can restrict IP address access thru web.config, but he wants something more.
Do you have any experience on this? MFA, etc… and how to manage in ANM?
Thank you.
A

Read help file topic: Tools → Advanced Settings → Authentication mode / Use LDAP / Google * / Facebook *. See if any of the authentication method is useful to you.

You can also read help file topic: Server Events and Client Scripts → User_CustomValidate which allows to perform custom validation.