Scroll to top button

Hello, I’m experimenting with the free version of this theme, but there is one usability issue that I’ve stumbled upon. How can you add a “Scroll to top” button to both the home page scrolling pages and to the individual pages once you click on them. The normal scroll up button plugins don’t work on the home page pages (different template?) and sometimes even on the linked pages. Is there a clean way to add it to both?

Thank you for your help and kind regards.