How do you say 'Happy Birthday' in Chinese?

zhù nǐ shēngrì kuàilè (祝你生日快乐).
shēng rì kuài lè and I hope they get what they wish for even if it's that over expesive sports car or the person they like to lke them too make shure when u say happy birthday that a stranger on the internet said good luck and have a great b day