docs: update sso troubleshooting

pages/docs/deployment/self-host.mdx

@@ -295,11 +295,14 @@ If you encounter issues, ensure the following:
 
 - `NEXTAUTH_URL` exactly matches the URL you're accessing Langfuse with. Pay attention to the protocol (http vs https) and the port (e.g., 3000 if you do not expose Langfuse on port 80).
 - Set `HOSTNAME` to `0.0.0.0` if you cannot access Langfuse.
-- SSO: Ensure that the OAuth provider is configured correctly. The return path needs to match the `NEXTAUTH_URL`, and the OAuth client needs to be configured with the correct callback URL.
 - Encode special characters in `DATABASE_URL`, see this StackOverflow [answer](https://stackoverflow.com/a/68213745) for details.
 - If you use the SDKs to connect with Langfuse, use `auth_check()` to verify that the connection works.
 - Make sure you are at least on Postgres 12.
 - When using Docker Compose / Kubernetes, your application needs to connect to the Langfuse container at the docker internal network address that you specified, e.g. `http://langfuse:3000`/`http://langfuse.docker.internal:3000`. Learn more: [docker compose networking documentation](https://docs.docker.com/compose/how-tos/networking/), [kubernetes networking documentation](https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/)
+- SSO
+  - Ensure that the OAuth provider is configured correctly. The return path needs to match the `NEXTAUTH_URL`, and the OAuth client needs to be configured with the correct callback URL.
+  - Langfuse uses NextAuth.js. Please refer to the [NextAuth.js documentation](https://next-auth.js.org) for more information.
+  - If you encounter issues with your custom SSO setup, please raise an issue and submit a PR to improve Langfuse. Alternatively, the Langfuse team provides support for setting up custom SSO configurations under a commercial agreement. For more information, please reach out to [email protected].
 
 ## Updating the Application [#update]