Thank you for all the help!
I am able to create subscriptions and verify that they were created. I also get the first GET request to my callback when the subscription is created however I’m still not getting any POST requests for new followers.
Do I have the end point correct? From my understanding I want my channel id to be the “to_id” field to see who follows my channel.
https://api.twitch.tv/helix/users/follows?first=1&to_id={MY_CHANNEL_ID}
Is there also anyway to find out what errors if any Twitch is receiving when they try to POST to my endpoint?