I have an application developed in ASP.NET MVC and SQL Server. 

Application is developed in a way that it can be used by multiple clients with Form-based authentication. We have more than 20 clients using the same app, no client-specific hosting. 

Clients are requesting us to implement Single Sign-On but these clients have multiple AD’s like client A has On-prem AD, client B has Azure AD, and so on...

1. Is this feasible to implement SSO with multiple ADs along with form-based auth on a web application
2. What would be an ideal solution for this scenario other than client-specific hosting

Thanks!