I(M) got a crush (and she doesn't know that I have a crush on her) and I'd really want her to be my gf. But the question is how do I propose. Like, what should I say?

If anything I learnt from movies, it was that when you are proposing someone to marry you, you say something similar to 'Will you marry me?', similarly, what to say when you want your crush to be your gf?