sequenceDiagram
  autonumber
  actor User
  User ->> Client: GET /b2t/execute
  Client ->> Server: GET /b2t/bitcoin/getnewaddress
  Server ->> Client: Return new Bitcoin address
  Client -->> Client: Create payment transaction
  Client -->> Client: Get new Tapyrus address
  Client ->> Server: GET /b2t/execute
  Server -->> Server: Create receipt transaction
  Server ->> Client: Return receipt transaction id
  Client ->> User: Return both transaction id