this is great! I've tested it and it required to trust the proxy

Merged, thank you so much!

In the next release, I will integrate OpenID Connect (OIDC) dynamically. This will allow the authentication flow to work seamlessly with multiple alias domains. The baseURL will be set dynamically based on the incoming request's host, ensuring that the app supports various domains and subdomains.

To ensure proper functionality, It's needed to update the OIDC provider’s callback URL settings to include all valid URLs, including aliases. This way, no matter which domain the user accesses, the OIDC authentication flow will work without issues.

Steps to Update Callback URLs:

1. Go to your OIDC provider's dashboard (e.g., Auth0).
2. Navigate to Applications > Your Application.
3. Under Settings, locate Allowed Callback URLs.
4. Add all valid callback URLs, for example:

   http://app.example.com/auth/callback,
   http://alias1.example.com/auth/callback,
   http://localhost:3010/auth/callback
   

5. If your aliases follow a consistent pattern, consider using wildcards like http://*.example.com/auth/callback to simplify the process.

By following these steps, we'll ensure that the authentication flow works smoothly across multiple domains and aliases.

Maybe @mirotalk-57bab571 can share some insights if this would be possible to fix upstream. Otherwise we have to disable alias domain support within the Cloudron package to not confuse users.