How to make a go to top Button in react

First off you will want to make your button and set it's position to fixed. This Will ensure that the button will stay in the bottom left or right of the screen, I recommend the bottom right, but whatever you choose is fine.

Then you will want to add an onClick event handler to your button and set it to run the following function.

        const scrollToTop = () =>{
            window.scrollTo({
            top: 0, 
            behavior: 'smooth'
            /* you can also use 'auto' behaviour
              in place of 'smooth' */
            });
        };

Full article with code examples here