Hello,
Being a C# developer for more than 5 years, so far I've worked on several applications that required consuming REST APIs to process user data. Typically, I worked on projects that required validating user information and license keys using REST API.
As it seems that you want to send receipt data to a REST API and generate a token, I would like to go through the details of the project and see if I can help you with the same.
Regards.