Separating Database Schema Creation from Phoenix Application Setup

Hi! When self-hosting Phoenix, is there a way to separate the database schema creation from the application? In my scenario, the database user that the application uses does not have write permissions (PostgreSQL), and the schema would be previously created by an external tool. If there's a way for me to get the migrations (so I can run with the other tool) and then configure the app to not run any DDL, that would be ideal. Thanks.