Make a refer and earn feature in unity game engine where user adds refferal code to earn game points

I am looking for a Unity game developer to create a referral and earn feature for a board game. The feature should allow users to enter a one-time use code to earn game points through referral links. The incentive for users to use the referral code should be game points which can be used in the game. This feature should be easy to integrate and work with the existing game engine. The developer should have prior experience with Unity game engineering, and be able to provide a detailed plan to accomplish the task.