Extract from the linked example:
HTTPClient http; //Declare object of class HTTPClient
http.begin("http://192.168.1.88:8085/hello"); //Specify request destination
http.addHeader("Content-Type", "text/plain"); //Specify content-type header
int httpCode = http.POST("Message from ESP8266"); //Send the request
String payload = http.getString(); //Get the response payload
Serial.println(httpCode); //Print HTTP return code
Serial.println(payload); //Print request response payload
http.end(); //Close connection
Change:
http.begin("http://192.168.1.88:8085/hello"); //Specify request destination
to match your environment say:
http.begin("http://myserver.com/barCodeSave.php");
Change:
int httpCode = http.POST("Message from ESP8266"); //Send the request
to match your environment say:
int httpCode = http.POST("barcode=12345689&submit=Scan");
If that does not help, post the full code you are attempting to use.