1. Create two address fields.
2. Give the address fields the CSS classes "addressOne" and "addressTwo" respectively.
3. Create a checkbox.
4. Change the Choices of the checkbox to "Yes"
5. Give the checkbox the CSS class "addressCheck".
6. Enter the following JavaScript:

   $(document).ready(function(){
     $('.addressCheck').change(function () {    
   
     var firstAddress = $('.addressOne').find('input');
     var secondAddress = $('.addressTwo').find('input');
       
       if ($(this).find('input[value="Yes"]').is(':checked')){
   
       for (i = 0; i < 6; i++) {
   
         $(secondAddress[i]).val($(firstAddress[i]).val());
   
       }
   
       } else {
   
        secondAddress.val('');
   
       }
       
     }); 
   }); 

From a usability point of view, it may be better to use a button for this operation.

You can add a button using Custom HTML.

In the HTML tab of Custom HTML, add the following:

<input id="copyAddressButton" type="button" value="Use the same address">

Then in JavaScript use the following:

$(document).ready(function(){
  $("#copyAddressButton").click(function(){
    
    var firstAddress = $('.addressOne').find('input');
    var secondAddress = $('.addressTwo').find('input');
    
    for (i = 0; i < 6; i++) {

      $(secondAddress[i]).val($(firstAddress[i]).val());

    }
    
  });
});