을 축하합니다

congratulations on

→ 을
phrase Rare #16,454
congratulations on Used after a noun to congratulate someone on an event or achievement. The object particle 을 attaches to the noun, and 축하합니다 is formal and polite.
KO: 졸업을 축하합니다.
EN: Congratulations on your graduation.

친애하는 커너 동무 생일을 축하합니다

Happy birthday, dear Comrade Kerner.

— 굿바이, 레닌 (2003)