Postgres-tsquery syntax error

What I’m trying to do:
I am trying to use postgresql query(first time) as below, getting syntax error. How to resolve it?

Code Sample:

# code snippet

test2 = app_tables.words.search(suffix=q.full_text_match("SELECT '(wal|walk)'::tsquery",raw=True))

Documentation says: For more control, set raw to True, THEN provide a full PostgreSQL tsquery pattern.

What is meaning of “Then” here?