We try making scroll to top button using the native anchor tag and a button from the master page, but that unfortunately doesn’t work. Because, the anchor gets duplicated throughout the pages (All pages) and you can’t link to it once.
Here is the widget I have made for you to make your muse website easy. Click here to Download the Scroll to top for Muse and add it to muse. Simply add the graphic style of the button you want to use and Voila! you are done.
Here is the video tutorial for the widget: