Using a fixed token
Using a fixed token is pretty straightforward. Just pass your application's client ID and your token to StaticAuthProvider.
import { StaticAuthProvider } from 'twitch-auth';
const clientId = 'YOUR_CLIENT_ID';
const accessToken = 'YOUR_ACCESS_TOKEN';
const authProvider = new StaticAuthProvider(clientId, accessToken);
// As a minor optimization, you may pass the scopes of the token, but be sure they're correct in that case!
const authProvider2 = new StaticAuthProvider(clientId, accessToken, ['chat:read', 'chat:edit', 'channel:moderate']);