What is the best way to block specific URL for testing?

Question

I am observing a website with Google Chrome and Fiddler version 4.4.

The page is using AJAX to update its data. I want to block a specific URL to test what will happen i

Answer 1

What would you like to have happen?

Go to the AutoResponder tab. Tick Enable Automatic Responses and Unmatched requests pass through. Click the Add button. In the top box, enter http://example.com/yourURLisHere. In the box below it, select either 404_Plain.dat or choose *drop or *reset. The first returns a 404. The second just drops the connection if it sees the target URL. The third sends a TCP/IP RST packet if it sees the target URL.