Thank you to reading this and offering your help. I am using a Raspberry Pi Zero W and Python coding to trial this. However, the code is still not work, it never see the duration of the pulse.

SERVER_RESPONSE = b"""HTTP/1.1 200 OK\r\nDate: Mon, 1 Apr 2013 01:01:01 GMT\r\nContent-Type: text/plain\r\nContent-Length: 25\r\n\r\n ...