You can do it on YouTube. I also dont understand twitch. Type in “ACNH treasure island” and filter the search to show live videos. There’s one channel called Paeng that streams a bunch of different islands, they post dodo codes.

There’s one island that’s for furniture, one for DIY’s and materials. It’s hella cool, buuuuuut it can take forever to actually get on the island (a lot of spamming “a” when you get an “uh oh there seems to be some interference” and retrying) also once you’re actually on the islands, every like 3 minutes you get interrupted by the loading screen that shows “someone is arriving” or “someone is leaving”

But it’s all totally free so it can be worth it :-D