Retrieve OUT refcursor store procedure in pgx pool

Hi admin,
here is my postgresql store procedure:
CREATE OR REPLACE PROCEDURE test.get_all_merchant (
rs out refcursor
)
LANGUAGE plpgsql
AS $procedure$
BEGIN
OPEN rs FOR
SELECT
*
FROM
test.tb_merchant
WHERE
s_state = 'approved';
END;
$procedure$;

I don't know how to use pgx pool to get out parameter in golang (here is rs refcursor). Can you guide me?

Start by reviewing the pgx pool APIs and PostgreSQL procedure behavior for OUT refcursor parameters. Reproduce the supplied test.get_all_merchant procedure and determine how its cursor can be retrieved in Go. Done means a documented or tested example showing the complete retrieval flow.

Written by the indexing model from the issue text.