Yes, that was it! I added it to the env section of my TOML and the value is set and I finally got past that error message!
[env]
PORT = "8080"
NODE_ENV = "production"
After the first try, I saw what you said you saw, “The server does not support SSL connections”. Then I removed that PGSSLMODE secret and got past that error as well.
Unfortunately, I now have a different unexpected error. When I hit one of my queries, I get the following postgres error error: 'relation "recipes" does not exist', where recipes is the table that query is based on. But I already created the the tables with their schemas and when I interact with the db in CLI, I see the tables. When the db was first created, I got that error, but then I ran my schema migration to to create all the tables in the CLI and they show up there.