docs: Add a note about webui

Author: MeSoftHorny

docs/docs/index.md

@@ -57,6 +57,7 @@ Simply extract the downloaded zip file into the folder where the old version is
 
 ## System requirements
 - **Game**: **Full client+**  
+> **Note:** **"Custom Battles"** or **"Custom Difficulty"** (Test Flight): Requires enabled **"Allow web UI"** option.
 > **Note:** **DEV Server** or **Minimal client** users, see [Troubleshooting](troubleshooting.md#not-working-with-dev-server) for a workaround.
 - **OS**:  
   **Windows**: 7+.  

docs/docs/troubleshooting.md

@@ -1,3 +1,7 @@
+## WTRTI doesn't work with "Custom Battles" or "Custom Difficulty" (Test Flight):
+Make sure you enable the **"Allow web UI"** option in the custom settings.  
+This option was added in the "Hornet's Sting" update (2.45).  
+
 ## Radar Altitude do not work
 The value “radio_altitude” may be missing in telemetry on some aircraft, because the aircraft does not have a radar altitude or the value is displayed on a digital device (modern jets).  
 The game just doesn't provide values from HMD or MFDs.