[docs] Add port to receive message docker run command

docs/site/content/en/docs/how-to/receive-messages/index.md

@@ -50,7 +50,7 @@ Below the list of all events that WhatsApp HTTP API sends to your.
 Run the bellow command and see look at the logs - it prints body request for all events that happen in your WhatsApp!
 
 ```bash
-docker run -it -e "WHATSAPP_HOOK_EVENTS=*" -e WHATSAPP_HOOK_URL=https://httpbin.org/post devlikeapro/whatsapp-http-api
+docker run -it -e "WHATSAPP_HOOK_EVENTS=*" -e WHATSAPP_HOOK_URL=https://httpbin.org/post -p 3000:3000 devlikeapro/whatsapp-http-api
 ```
 
 ### Examples