There is an option to see what your page looks like in the builder.
Look in the top right area of the window for… “ Preview”
That will allow you to see your selected variant before it’s live. But sometimes I’ve noticed scripts that don’t fire off in the preview. It’s always best to test things like this from the live URL. If you need to do that, just add 100% of your traffic to the new variant from the overview page. This way you know you will land on the proper variant to test.