That’s not a problem either. When you create an alternative using Nelio A/B Testing, you do it using a special admin page in our plugin. In other words, you don’t create a full page /pay and then set it up as /checkout’s alternative.
Moreover, an alternative created with our plugin is not accessible via a URL (it has none). The user accesses the original URL (/checkout) and the content of the page is automatically replaced with the alternative’s (if needed).
Please, feel free to subscribe to our service and give it a try yourself. You have a 14-day free trial period.