Some options
- The extension can connect to chat and read chat itself, and respond to commands, exactly like the chat on the page does (not the best idea)
- You can create a chat bot on your EBS, and the chat bot connects to the chat channels needed and reads chat, and when a chat command occurs relay that over Twitch Extension PubSub to your extension (preferred idea)
The latter works better as then you are not wasting viewer CPU cycles reading chat and every extension instance reads from the same hymn sheet/triggers at the same time. And works better for users on mobile, where the extension and your JS might not be running all the time
How to connect to chat has not changed, as chat doesn’t belong to Kraken or Helix. And the post you found refers to a undocumented API third parties are/were not supposed to be using anyway.
Thats covered here: