Jack111

I am trying to write the following Racket function
(define (unique-right lst)
  (foldl (lambda (x y) (cons (empty lst) (filter (lambda (z) (not (= x z))) y))) ))
(check-expect(unique-right '(1 4 2 1 5 4))'(2 1 5 4))
But my output is (4 5 1 2), any hint? what should I do  from here?