My flow looks like, but I have tried multiple different ways to figure out how to do this when my stuff is only known at runtime.

with Flow("test") as flow:
    client_name = Parameter('client_name', default='client_demo')    
    client_context = get_client_context("C:/.secrets/client/", client_name)
    db_exec = PostgresExecute(
        host=get_value(client_context, 'oltp_host'), db_name=get_value(client_context, 'oltp_database'), user=get_value(client_context, 'oltp_user'), query="SELECT do_something()"
    )
    result = db_exec(password=get_value(client_context, 'oltp_pass'))