Someone on the TwitchDev Discord solved it for me.
The problem was that channel names should just be a username, not a URL. Also the username should have been my username, ‘gamershork’, instead of the bot’s registered name.
So instead of
'https://www.twitch.tv/gamershork',
'https://www.twitch.tv/nanbreadloaf'
it’s just
'gamershork',
'nanbreadloaf'