The default postgres driver support is psycopg2 for synchronous fixtures, and asyncpg for async fixtures. If you want to use a different driver, you can configure the drivername field using the pmr_postgres_config fixture:
@pytest.fixture def pmr_postgres_config():
PostgresConfig(drivername=’postgresql+psycopg2’) # but whatever drivername you require.
Note however, that the asyncpg driver only works with the async fixture, and the psycopg2 driver only works with the synchronous fixture. These are inherent attributes of the drivers/support within SQLAlchemy.