A question about coupons

I am currently setting up a “subscription box” for the Letters from the North Pole on a particular marketplace. They ask to provide a unique, ongoing coupon code, evergreen coupon code (no expiration date). I would like to create a coupon that can be used only ONCE per customer. I am not sure how to do it (or if it can be done).

Initially, I was thinking of making a coupon to give 4 months for the price of 3 months, but I have no idea if it can be done, so I figured that if I set up a 25% discount, it could work BUT I don’t know how to set it up so that someone does not start, cancel and start again with the same discount over and over again.

In the backend, there is a Max Uses and a Uses (Counter) . I assume that is for everyone and not based on individual customers. Am I correct? If so, is there a way to get the coupon to be used only once per customer?

Thanks.