How do i make a gamepass that can be bought more than once?

I wanted to make the gamepass so more people can buy it more than once.

Those are called 'Developer Products'. They can be bought more than once. Let's suppose you have currency called 'Cash' in your game. If player needs to buy cash, you will use Developer Products. They can pay robux and get in-game cash. And that cash can be bought multiple times. Game passes are one-time purchases only.

Here is a link to learn more about Developer Products:

https://developer.roblox.com/en-us/articles/Developer-Products-In-Game-Purchases

And a video link:

https://www.youtube.com/watch?v=QC2bDZsFiz4

Hope it helps