1. open the base layer
2. add a new button where you want it
3. on the configure link page, instead of http, select js:
4. in the link input box add: topFunction();
5. Click on the source Code button on top of the working area
6. Click on the Plus sign to add a code block
7. The New code block input screen will appear.
1. Put the name of your choice
2. select type: Javascript
3. Position EndBody
4. Add the code to this block
5. Make sure to replace WEb15ef1c0ae with your button's id

// Get the button let mybutton = document.getElementById("WEb15ef1c0ae"); // When the user scrolls down 20px from the top of the document, show the button window.onscroll = function() {scrollFunction()}; function scrollFunction() {   if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {     mybutton.style.display = "block";   } else {     mybutton.style.display = "none";   } } // When the user clicks on the button, scroll to the top of the document function topFunction() {   document.body.scrollTop = 0;   document.documentElement.scrollTop = 0; }