When building an Apple App Site Association file (AASA or apple-app-site-association
file), it's very easy to get it wrong. That's why Apple built a "App Search API Validation Tool" (ref1, ref2).
This seemed to be available as recently as June 2022 at https://search.developer.apple.com/appsearch-validation-tool/. However, that site now redirects to a generic page about universal links.
I would like to use Apple's tool to validate my AASA file because when I chose my build in App Store Connect, it shows that there are problems with my AASA file:
DOMAIN STATUS: 1 invalid domain
CACHE STATUS: Cannot Reach AASA File
DEBUG STATUS: Invalid Entitlement: Unknown ID
How do I access Apple's App Search API Validation Tool?
I know there are 3rd party AASA validators:
... however, these are not built by Apple, so may not be as thorough as Apple's tool. Case in point, my AASA file succeeds on both of these sites, even though it fails on App Store Connect.