how do i add downloaded scripts

evry time i try to drag the scripts into the assets window this message poppes up in the console: Dragged directory contains a project’s Library folder (PauseMenu.js). This is not allowed.
UnityEditorInternal.InternalEditorUtility:ProjectWindowDrag(HierarchyProperty, Boolean)
UnityEditor.DockArea:OnGUI()

You are getting this error because you are attempting to drag an entire Unity Project directory into your existing project. If you wish to import a single script from the project, open the Directory and drag the single script you wish to import.

It is strange that your file you’re attempting to drag is called “PauseMenu.js”, is it really a JavaScript file? Or is it a directory as the error indicated?