Update HTTP REST API

HTTP-REST-API.md

@@ -34,6 +34,24 @@ This document reflects the API **exactly as implemented** in the server code.
 
 > The server listens on `127.0.0.1:<API_PORT>`, where `<API_PORT>` comes from your runtime configuration (`config.json`).
 
+### 🔑 Authentication Configuration
+
+The `ApiUser`, `ApiPassword`, and `ApiPort` settings are stored in your **`config.json`** file.  
+These values are **read directly by the server** at startup.
+
+**Example `config.json` snippet:**
+
+```json
+{
+  "ApiPassword": "",
+  "ApiPort": 10000,
+  "ApiUser": "repertory"
+}
+```
+
+- **ApiUser** → Username for API authentication  
+- **ApiPassword** → Plaintext password (hashed internally during requests)  
+- **ApiPort** → Port number the API server listens on
 
 ---