If you have a script manager and you want to download some script without installing it, this script will help
< Feedback on GreasyFork: download script button
I don't understand this. What's the purpose of the promise?
I guess you've meant that older implementations of the GM.xmlHttpRequest do not return a promise, so the script won't work. This should be fixed now
const response = await GM.xmlHttpRequest({...});
to
const response = await new Promise((resolve, reject) => {
...