Troubleshooting authentication issues in the Remix Supabase kit

Supabase redirects to localhost instead of my website URL

This is most likely an issue related to not having set up the Authentication URL in the Supabase settings as describe in the going to production guide;

Cannot Receive Emails from Supabase

This issue may arise if you have not setup an SMTP provider from within Supabase.

Supabase's own SMTP provider has low limits and low deliverability, therefore you must set up your own - and only use the default Supabase's one for testing purposes.

Cannot sign in with oAuth provider

This is most likely a settings issues from within the Supabase dashboard or in the provider's settings.

Please read Supabase's documentation on how to set up third-party providers.