What's the easiest way to enable IIS debugging?

Question

IIS

Server 1c, IIS is installed on the server.
1c published on the web server. There is also a website from which orders are pushed to this server in 1s.
Everything worked.
After some work by a php programmer on the website, orders from the website stopped coming at 1s.
Wireshark installed on a Windows server shows that xml with an order comes to it, but IIS sends a 500 error in response. In addition to wireshark, this can also be seen in the IIS logs, but there it's just three lines

GET /iisserver/ws/CustomerOrders.1cws wsdl 80 -  - - 200 0 0 375
POST /iisserver/ws/CustomerOrders.1cws - 80 - PHP-SOAP/7.1.29 - 200 0 0 62
POST /iisserver/ws/CustomerOrders.1cws - 80 - PHP-SOAP/7.1.29 - 500 0 0 125

In the registration log 1s, in general, it is empty on this score.
How to find out what you don't like in POST IIS or 1c?

Answer 1

As a rule, error 1c is described in the response body.
Well, in IIS there should already be something like: IIS Manager - <Specific Server> - Sites - - <Virtual Application Name> - Error Pages - Change Settings ... If the server encounters an error, return to Detailed Error Messages.