Sounds like you are getting a user access token rather than an App Access Token, which might prove some fun if you are not intending to ask uses to login.
This is a nodeJS example for getting an App Access Token, and you can fetch a new App Access Token automatically without user intervention
Twitch doesn’t provide search API that will do what you want.
will return streams and you can fetch all the streams and look for ones using the Speed running tag
First you’d have to get the Tag ID for speed running from
I believe they use a “known list” of streamers so they are using Webhooks to see whom is live. (Or looking them up 100 at a time).
So they don’t have to search they just lookup known users of their website.