I cannot find any information on this online, and Apple support wasn't able to help either. I cannot figure out how to submit an app build to Apple's beta app review so it can be made available for external testing on TestFlight.
I have the build, it shows up in the App Store Connect TestFlight tab as "Ready to Test". I can add it to internal testing, and it works fine. With that said, when I try to add it to an external testing group, the build doesn't show up.
Has anyone experienced this? Is there another way to submit an app for Beta App Review, or is there something else I need to do?
I figured it out! If anyone else has this issue, it's because when I built the app in Xcode in inadvertently selected "internal testing only". After deselecting that, everything works properly!