https://developer.apple.com/documentation/storekit/in-app_purchase/testing_in-app_purchases_with_sandbox
But a number of things don't jive:
The documentation indicates there should be a Sandbox Account section on the device in Settings > Apple ID, iCloud, iTunes & App Store. This is not the case for me. I simply don't have that section.
I do, however, have a Sandbox Account section in Settings > App Store. I can successfully sign in my sandbox account here. I'm able to then make sandbox purchases just fine.
But, when I tap on the sandbox account I get the option to Manage it. I would expect this is where I could test cancellation, resubscribing, etc. But all it does is present a page that says "Cannot Connect" with a Retry button.
I'm running the app via Xcode 12 beta 6. My test device is running iOS 14 beta (18A5373a).
The instructions seem straightforward. But I feel like I've missed something simple as I cannot find other folks reporting the same issue after the announcement that this is available. Any help would be appreciated as the cancellation, renewal, etc process has been a black box to develope against until now.