The created APK name should be: → "CalculatorOK1.apk".
To get this, the name of the AIA should be → "CalculatorOK1.aia" (appName.aia).
If you logged in with the correct AI2 account (mueller69@...), the packageName should then be:
→ appinventor.ai_mueller69.CalculatorOK1. (EDITED)
The packageName in AI2 is: "appinventor.ai_email.appName". In your case: appinventor.ai_mueller69.appName