You requsted as “OAuth Client Credentials Flow (App Access Tokens)”
You need a “OAuth Authorization Code Flow (User Access Tokens)”
3) On your server, get an access token by making this request:
POST https://api.twitch.tv/kraken/oauth2/token
?client_id=<your client ID>
&client_secret=<your client secret>
&code=<authorization code received above>
&grant_type=authorization_code
&redirect_uri=<your registered redirect URI>