Hi Jeyson.

its seems to be some issue with the permissions: could you check  the user executing the truncate command has the necessary permissions to modify the table, at the best the user sould have permission to all tables.

connect to PostgresSQL with a user who has enough permissions:

here is how you can give the permission: GRANT TRUNCATE ON TABLE tablename TO username; and

GRANT TRUNCATE ON TABLE XXX TO user;

i hope it will help you!

BR,
Bilal