That being said, I’m not sure why it doesn’t work, only thing I could see being an issue is the content of your pastebin: two brackets are missing…
if(!a.hasOwnProperty(`kind`)){
throw new Error(`${u} Set your subscriptions to public to get results: https://support.google.com/youtube/answer/7280190`);}
a.items.forEach(c=>b.push(c.snippet.title));
d=b.slice(0,3).join(`, `);
d?`${u} Your last subscriptions are: ${d}`:`${u} No subs found!`;}
catch(e){`Nightbot cannot output a response: `+e.message.slice(0,200);}
It would have been helpful if you linked the original post you got the code from.
Also, I don’t think leaking your key is a good idea.
After investigating (there are so many xloss with the same profile picture on YouTube, it would have been good to have your user ID), it looks like your key has expired and that’s why you get the error.