When you customize Magento 2 to your needs, conversion is everything. So part of the customization process will definitely include the checkout process, including the success page that is visited once the checkout is completed. But when you refresh the success page, the session is cleaned up and you are redirected back to the cart.
This extension is ment to solve this specific issue. Instead of hacking the Magento 2 core, you can install our Magento2 extension in a simple and clean manner, and preview the success-page at any time. You simply point your browser to the preview URL and voila, there's your success page:
http://MAGENTO2/checkouttester/index/success
You can also test a specific order with the following:
http://MAGENTO2/checkouttester/index/success/order_id/1234
If you like this extension, make sure to view our EmailTester2 extension. We do not want to build a shop without it.