The text “PathCopy” it’s blue because it’s a link to plugin web page, so you can download it directly. Just click on that blue text, it will redirect you to the official SketchUp Extensions page.
PathCopy is awesome for complex arcs and lines and I use it all the time. Note that you need to ‘Weld’ the multiple lines together if your path made up of multiple arcs/lines. If your copying along a single arc, the regular protractor/rotate tool works well too. Hold the modify key (option/alt) to create what’s called a Polar Array…then copy it to end of path and enter “/(number of copies you want)”…you can change your mind as well until you’re happy and then finalize the rotate command to lock it down.