At first I was a little confused by what you meant by generating types from a database. I guess it's something particular to postgres or relational databases? I checked supabase's website and says it uses Postgres.
I only know how to use MongoDB. And the way it works is that I create the schema, and the implied type, on my app (with Mongoose ODM) and don't have to worry about how the database handles it. Because Mongo, being document-based, doesn't use any schema whatsoever.
Or perhaps I am just too naive and don't fully understand what you tried to do 😅