Crashes when using keychainAccessGroup

[zakmcrbit]

First I implemented this library successfully in an app extension but sharing stored values between my app and the extension didn't work.
Then I tried setting the .keychainAccessGroup as well:

self.defaultsAppGroupSecure = SecureDefaults(suiteName: "group.com.company.appname.AppGroup")
self.defaultsAppGroupSecure!.keychainAccessGroup = "com.company.appname.KeyChain"
        
if !self.defaultsAppGroupSecure!.isKeyCreated {
     self.defaultsAppGroupSecure!.password = "password"
}
        
self.defaultsAppGroupSecure!.set(true, forKey: "storedValue")

It throws "SecureDefaults.swift:218: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value".
It seems like the internal key property isn't set. I had tried to set it manually but it wouldn't work.

What am I doing wrong?

[zakmcrbit]

I forgot to include the TEAM-ID at the beginning of the keychainAccessGroup parameter so it doesn't crash but still can't get to share the same parameters between the app and the extension.