ESP8266 WebServer - how to see additional headers in request?

I have webserver on esp8266, and i would like to have php-script running on my NAS to talk to this webserver, using info in header. The problem I cannot see headers on esp8266 side. My code on esp8266 side:

  //show headers
  String message ="";
  message += "Header Count: ";
  message += server.headers(); 
  message += "\n";
  for ( uint8_t i = 0; i < server.headers(); i++ ) 
    message += " " + server.headerName(i) + ": " + server.header(i) + "\n";
  server.send ( 200, "text/plain", message );

I did not make php-script yet, I am sending request using Postman tool, see screenshot:

It always return only one header item, name is Autorization with no value:

Header Count: 1

What am i doing wrong?

Similar issue discussed at with possible example solution at

Thank you, it works!
Does it mean I have to know all interested header names in advance? Can I see just all headers?