Saml based authenication for multiple IDP's in SharePoint Online

Hi Team,

Need Advise!

We are migrating our SharePoint 2013 to SP Online.

In SharePoint 2013, we support SAML based authentication for multiple IPD's with proxy setup. We allow users to choose their IDP's from our custom page and user will thereafter be redirected to their's IDP's to authenticate.

We would like to consume this on-premise setup and provider authentication to all our IDP's to our SharePoint Online tenant.

How do we achieve this? Any documentations or suggestions would be highly appreciated.

Thank you!