How do I figure out the URL for the thank you page wizard?

How do I figure out the URL for the thank you page wizard? I've tried several versions and none of them has worked. Isn't there a way to browse to it to get the accurate address?

Open your form on the Form Builder, then:

1. Click on "Setup and Share" tab on the form builder toolbar

2. Click on "Thank You"

3. Select "Custom URL" option and enter a URL from your own web site.