DOCS: BACKEND_API_URL reverse proxies

Signed-off-by: jokob-sk <jokob.sk@gmail.com>

docs/REVERSE_PROXY.md

@@ -1,5 +1,13 @@
 # Reverse Proxy Configuration
 
+> [!TIP]
+> You will need to specify the `BACKEND_API_URL` setting if you are running reverse proxies. This is the URL that points to the backend server url (including your `GRAPHQL_PORT`)
+>
+> ![BACKEND_API_URL setting](./img/REVERSE_PROXY/BACKEND_API_URL.png)
+> ![NPM set up](./img/REVERSE_PROXY/nginx_proxy_manager_npm.png)
+
+## NGINX HTTP Configuration (Direct Path)
+
 > Submitted by amazing [cvc90](https://github.com/cvc90) 🙏
 
 > [!NOTE]
@@ -10,8 +18,6 @@
 
 <br/>
 
-## NGINX HTTP Configuration (Direct Path)
-
 1. On your NGINX server, create a new file called /etc/nginx/sites-available/netalertx
 
 2. In this file, paste the following code: