Thanks, I’ll give it a try, although the example in the documentation uses the client-id, not an app token:
curl -H 'Client-ID: uo6dggojyb8d6soh92zknwmi5ej1q2' \
-X GET 'https://api.twitch.tv/helix/webhooks/subscriptions?first=10&after=eyJiIjpudWxsLCJhIjp7IkN1cnNvciI6IiJ9fQ'