Found this thread when searching how to connect access to Supabase earlier tonight.
Created an account with Supabase earlier today, as in the process of developing a web app and wanted to ensure Supabase would work with Access (which is our current in-house offering).
Took me about half an hour to set up some basic tables and then used
psqlodbc - PostgreSQL ODBC driver to create a DNS.
Used the connection info found at the bottom of the Database page under Settings in Supabase to enter and create a 32-bit ODBC system DNS using PostgreSQL Unicode driver. Tested the connection and done.
Have now linked to external data in Access and updates appear in both instantly.
Pretty impressed, but still have some experimenting to do.