Create Auth Session for External IDP User

NOTE: In order for the session cookie to be set properly this API needs to be redirected to from the browser. The redirect URL should use the vanity domain of the tenant that the session is associated to.

Creates a new auth session for the user and returns a response containing a redirect to the configured redirect location. The response will also include the session cookie. Likewise, if state was passed into the original signup request then a state query parameter will be appended to the redirect URL with the original state value.

The redirect URL that gets returned will resolve in the following order:

• If a Signup Workflow custom redirect URL is configured, that will be returned.
• If a client ID was passed to the signup request and a client login URL is defined, then that will be returned.
• Otherwise, the application login URL is returned.