Postgres uuid

CREATE OR REPLACE FUNCTION create_role()
RETURNS TEXT AS $$
DECLARE
  _uuid text := (select replace((select gen_random_uuid()::TEXT), '-', ''));
BEGIN
  execute format('create role u%s',_uuid);
  RETURN _uuid;
END;
$$  LANGUAGE plpgsql;

select gen_random_uuid ();

select replace((select gen_random_uuid()::TEXT), '-', '') ;

create or replace function create_user_readonly (
  unm varchar,
  pwd varchar
)
  returns varchar(10) as $$

begin

  execute format($f$create role %I login password '%s'$f$,unm,pwd);
  execute format('alter role %I set transaction_read_only to on',unm);
  return 'success';

end;

$$ language plpgsql;

CREATE OR REPLACE FUNCTION jb()
RETURNS TEXT AS $$
DECLARE
  rtv TEXT := 'test';
  _uuid text := (select replace((select gen_random_uuid()::TEXT), '-', ''));
BEGIN
  -- PERFORM 'test';
  -- PERFORM uuid;
  CREATE ROLE _uuid;
  RETURN _uuid;
END;
$$  LANGUAGE plpgsql;