You might want to look at the correlation course in our academy (https://academy.neotys.com/courses/design/lessons/design-...), from memory, you are selecting a category such as fish so the request looks like catagoryID=FISH&id=152342343, the id is dynamic and changes every time. This value is provided by the server so you need to correlate the value you are being sent to the one you are sending back, like batting a ball back over a net. If the server send you abc, you return abc. Use the flag function to find in which response the id is sent to you.