Q: Does the Coupon form have to be filled out every round?

A: No, you do not need to, as Coupons are completely optional.

If you're doing multiple during one round, you can just fill out one form (since the form allows for checkboxes), although if you want to fill it out each time for different coupons, that's ok too.

If you're doing it during multiple rounds (such as doing PV during R1 and then doing Promo during R2), you should fill it out again.