I have been building the app with XCode 13 Beta and submitting the same to TestFlight so that our internal testing team can test it(I am using the Command Line Tools XCode 13.0 (13A5155e). It allowed me to submit several builds to Testflight until this morning. However, it is complaining now that I am using an invalid version. See below
ITMS-90534: Invalid Toolchain - Your app was built with an unsupported SDK or version of Xcode. If you plan to submit this build to the App Store, make sure you are using the versions listed in https://help.apple.com/xcode/mac/current/#/devf16aefe3b or later.
Since we are using iOS 15 features, I cannot build with XCode 12.x.
Your help is appreciated.