User_saml app: How do we get master realm admin users if configuration only allows a single IdP setting?

Hi,

I have keycloak (SAML identity provider) running with 2 realms: master (the one with admin users) and public (the one with non-admin users)

I’ve installed the user_saml app into NextCloud, and I’ve got it working with the IdP settings of the public realm.
It has a path like this: https://security.companyname.com/auth/realms/public

But the app only allows one such IdP setting.

The admin users are part of a different realm: https://security.companyname.com/auth/realms/master

How can I be able to sign on as admin when I cannot configure the master realm alongside the other public(non-admin) one?

Thanks