- Pick a language.
- Use an existing Twitch Library to connect to chat or write your own/use your own
- Decide on the command and add programming to add uses whome run the command to said list, along with the data they pass.
- Decide how to get that list to the streamer.
Personally, if I was building this I’d probably do it in NodeJS using my existing bot template. And store the list in redis. Then create a webpage for the streamer to use that displays the contents of the redis list.