You need to have a @require in the user script header to load jQuery. Something like:
// @require https://code.jquery.com/jquery-3.6.0.min.js
(Selecting your desired version from the of list of available versions of jQuery)
You need to have a @require in the user script header to load jQuery. Something like:
// @require https://code.jquery.com/jquery-3.6.0.min.js
(Selecting your desired version from the of list of available versions of jQuery)