How do I Create a Read-only User

CREATE USER newuser123 WITH PASSWORD 'foobar123';
# ALTER USER newuser123 WITH SUPERUSER; #Uncomment for superuser

GRANT CONNECT ON DATABASE database_name TO newuser123;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO newuser123;
GRANT SELECT ON ALL SEQUENCES IN SCHEMA public TO newuser123;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO newuser123;