How options actually work on binance?

So, often when buying bitcoin I set up shopping for orders at specific costs. I was speaking about this with a pal who buys stocks utilizing choices, and he stated:

You possibly can promote puts on the strike you needed to purchase, if the worth is on the cash, you buy the asset on the worth you needed, if its out of the money you get the premium.

Wich is cheap, I did a check with a small sum of money and bought a put, but because it was out of the money the the contract expired I solely stored the premium, what occurs if the contract expires on the money?