Looking at that I don’t see any obvious reasons why it would be erroring for you. The data being passed to the crypto function (which your error message indicates it’s being passed NaN) is just event.headers['Twitch-Eventsub-Message-Id'] + event.headers['Twitch-Eventsub-Message-Timestamp'] + event.body, so I’m not sure how that’s becoming NaN for you, as all the headers/body seems to be correct.