Troubleshoot

Android

ERR_UNSUPPORTED_API_LEVEL: Unsupported API level: 34

Use the Device Manager (Android Studio) to configure a device that has a lower API level.

iOS

xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance

sudo xcode-select -r