Current Version: V3.0.1
Want to work with Twitch API inside Unity? 
StreamLinked is the package designed to be the 1 to 1 comparison to Twitch's documentation website.
From OAuth management to IRC and Twitch Chat message building in TextMeshPro (Emotes and Animated Emotes included) to EventSub and lastly API Endpoints.
I built this package as trying to work with Twitch in Unity was always a nuisance and frustrating experience. So after many endless nights I've compiled as simple as possible implementation while also leaving parts open for user expansion and implementation.
For example if you want to call a Twitch API endpoint, make sure a client is available in the scene with your credentials to automatically get the authentication token and in your script, call TwitchAPIClient.MakeTwitchAPIRequest<GetUsers>().
If you see something on Twitch's Documentation website, it should be worded and presented the same in Unity.
Guides included to get you started too.
Supports Async and Coroutine implementations.
I'm always looking for areas to improve so feel free to let me know.
Does not support WebGL due to the inclusion of System.Net
https://assetstore.unity.com/packages/tools/network/streamlinked-api-auth-eventsub-and-irc-for-twitch-273978