How to create User through API in Oracle apps?

API : User Creation

DECLARE
ln_user_id NUMBER;
ln_resp_id NUMBER;
ln_app_id NUMBER;

BEGIN
fnd_user_pkg.createUser( 'TEST1','','WELCOME123');

SELECT user_id
INTO ln_user_id
FROM fnd_user WHERE user_name = 'TEST1';

SELECT responsibility_id,
application_id
INTO ln_resp_id,
ln_app_id
FROM fnd_responsibility
WHERE responsibility_key = 'SYSTEM_ADMINISTRATOR';

FND_USER_RESP_GROUPS_API.insert_assignment( ln_user_id
,ln_resp_id
,ln_app_id
,NULL
,SYSDATE
,NULL
,NULL );

COMMIT;
END;