Trying to install both with alt store and sideloadly gives the same error message on my iphone 13 ios 16.3.
Using app ID "LingoDeer iOSGodscom" with id *CENSORED*
Signing...
Connecting...
Uploading, please keep device screen ON!
Installing...
Installation failed: 0 AppexBundleMissingClassOrStoryboard (Appex bundle at /var/installd/Library/Caches/com.apple.mobile.installd.staging/temp.hGOaXp/extracted/LingoDeer - iOSGods.com.app/PlugIns/com.lingodeer.J78M3SK4M8.LDWidget.appex with id com.lingodeer.J78M3SK4M8.LDWidget does not define either an NSExtensionMainStoryboard or NSExtensionPrincipalClass key with a string value in the NSExtension dictionary in its Info.plist)
Done.
Could sideload to my m1 pro macbook without problems.