Keycloak External IDP SAML - Assertion Consumer Service Metadata

Hello, I would like to connect an external SAML Identity Provider. I am also redirected to the login page of the external provider. However, when I log in, I get an error stating that the Assertion Consumer Services are not stored. However, I cannot specify them in the configuration of the external service provider.

Can anyone help me find out where I can specify this?

Many greetings Christian Renken