General Issues
url = "https://id.twitch.tv/oauth2/authorize?response_type=code&client_id=qrwctu82red26ek1d320lpr4uqbz9e&redirect_uri=http://clip-maker.com/redirect-from-twitch&scope=user:read:email clips:edit"
should be
url = "https://id.twitch.tv/oauth2/authorize?response_type=code&client_id=qrwctu82red26ek1d320lpr4uqbz9e&redirect_uri=http://clip-maker.com/redirect-from-twitch&scope=user:read:email+clips:edit"
Secondly, consider moving to SSL for security/user happiness on your callback
And to your actual issue
This usually suggests you accidentally used the code twice. And thus the second/final one failed
I can’t see anything wrong given the information/code you have provided.