You are likely getting an error in your networking overview stating you are not allowed to use that resource.
Please add the following line to the top of your PHP page and try again:
Sorry for question on old post, but what does this do exactly?
Or more simply
Should it be used in all php scripts/pages in association with Construct?
I am troubleshooting an issue with an AJAX POST from Construct. I added this and it didn't solve the issue so don't know whether it's safe to leave in or may cause more issues.
Brief answer is fine as if I want the nitty gritty I assume I can read here https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS