Twitch said that they plan to offer hosting streamer configurations at some point. Until then you’ll have to create your own back-end architecture like Samiff said.
I can highly recommend either AWS Lambda or Google’s Cloud Functions/Firebase Functions. They both have good free tiers and easy integration with a database.
If you use a node back-end: I used jsonwebtoken to verify & decode the signed JWT token. And don’t forget to decode your extension’s secret before passing it into the verify function: Buffer.from(yourSecret, 'base64').
Hope I could help a litte. Cheers!