Add instructions for getting message ID

docs/votes/rlhf.mdx

@@ -15,3 +15,11 @@ At the moment, the RLHF feature is only available to a few users. We are working
 ## What can I do for now?
 
 You can still use the votes endpoint to vote on the quality of the AI response, and you can use the history endpoints to see the history of votes.
+
+
+## From where I can get the message ID?
+
+You have two options:
+
+1. In the chat widget, after every AI response you will get a socket event with the name `vote`. The event will contain the message ID of the last AI response.
+2. Or you can use the `history` endpoint to get the history of votes and find the message ID of the last AI response.