Product subscription model

This is not a question we can answer, it's much, much too broad for a little text box like this!

Start with Google: Product subscription model C#[^] and follow a few links, rean teh information on the other end, and try to refine youe search until you either have enough knowledge to complete the exercise, or a much better idea of why you can't proceed. You can then ask a targeted question that we can actually answer if you need to.