Notice that this error can show up if you not safeguard the request to the action_manage_overlay_permission. Android developer:

In some cases, a matching Activity may not exist, so ensure you safeguard against this.

Verify you are not missing <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/> in the Android manifest.

But the error should propably come from await requestExactAlarmPermission2(); could you give more details on this code?