HTTP Applications

Hi I have a problem.
Maybe you too have followed this guide from this guy. But in the last part when using HTTP integration I have these problems:
In the last step, in ChirpStack-> Applications-> IOTAPP-> Integrations HTTP, I enter the IP address and port of the pc with windows followed by the path of the PHP.php file. The problem is that I don’t see anything on Windows: when I load the page localhost: 1234 / IIOTT / PHP.php I get an error message like " Wanrning : Attempt to read property" data "on string in C: \ xampp \ htdocs \ IIOTT \ PHP.php on line 7

Everything else done above works. So I have no problems related to XAMPP (and therefore to apache). it’s like it can’t send any json package to windows.