You get saml20-idp-remote.php from Keycloak. That is the curl commands in the post you saw here: Help setting up XDMoD and Keyclock(SAML) - #3 by tdockendorf. The URL might be slightly different on newer versions of Keycloak. For Keycloak 17+ it will be https://<keycloak server>/realms/<realm>/protocol/saml/descriptor. You can also get it by viewing the available protocols on Realm page inside Keycloak web UI. I believe you pass that descriptor information into simplsamlphp to generate the PHP file you need. I think it’s the metadata converter link.