Judge.me supports 2 types of coupons to incentivize your reviewers:
Static Coupon: Only 1 Static Coupon can be set at a time and we send the same coupon code to many reviewers. This is required when you enable Coupons feature, even when you've already uploaded Dynamic Coupons. The code can be shared online and you then need to accept the coupon for infinite orders as the code needs to work on multiple orders.
Dynamic Coupons: You can upload as many Dynamic Coupons as you want (more instructions here). This type of coupon codes helps you to make sure that only people who are supposed to get them can use them. When Judge.me sends a coupon to a reviewer, it will be consumed and no longer available. Therefore, different reviewers will receive different Dynamic Coupons, except for 2 cases: