Maybe "raw" wasn't the right term. I just meant SQL that I write myself and execute from the tool.
Since posting the original topic I did stumble over another that explained how to configure PGAdmin credentials, so I was able to connect to PGAdmin, which will serve my needs fine. Here's that topic, for others interested: https://community.retool.com/t/how-to-connect-to-the-retool-db-with-pgadmin-4/28967