On Whispers
Yes you could code a bot to automatically send a whisper to a user on an event.
But it’s considered “not reliable” to do that. As you’ll have deliverability issues.
It’s not a good use case for the whisper feature.
On Reply in chat
A better method is to send it via chat, but everyone will see if. Auto replies in chat with information/instructions is common and widely used.
So you just need a bot to listen to the relevant USERNOTICE events
Generally these days you’ll find most users already linked this Twitch to Discord anyway