Thread:Killroy1080/@comment-35327227-20191105183515/@comment-34929636-20191107145439

Can't.

All site-wide javascript must be approved by Fandom staff (mostly to prevent security issues).

Furthermore, site-wide modules (pre-made scripts) and javascript may only be uploaded by admins.

Personal javascript may be edited only by the user who wants it, and while not subject to upload restrictions, it will only apply to the user who loaded it.