How to fix 'App not found' on iOS (AppAvailability) - flutter

Question

I am launching a flutter app (App 1) from another flutter app (App 2) on Android and it works perfectly. However, I keep getting the same error on IOS. It does not recognize the package name.
I have tried with multiple apps but is the same result, it currently just recognizes the calendar package.
pubspec.yaml file flutter_appavailability
main.dart App 2
import 'package:flutter_appavailability/flutter_appavailability.dart';
//Future void method
if (Platform.isIOS) {
_installedApps = [
{"app_name": "example", "package_name": "com.flutter.example"},
];
print(await AppAvailability.checkAvailability("com.flutter.example")); //ERROR
//Widget build
return Container {
child : Row(
...
GestureDetector(
...
onTap: () {
Scaffold.of(context).hideCurrentSnackBar();
AppAvailability.launchApp(installedApps[0].["package_name"])
.then((_) {
print("App ${installedApps[0]["app_name"]} launched!");
}).catchError((err) {
Scaffold.of(context).showSnackBar(SnackBar(
content: Text(
"App ${installedApps[0]["app_name"]} not found!")));
print(err);
});
...
),
}
info.plist App 1
<key>CFBundleIdentifier</key>
<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
project.pbxproj App 1
PRODUCT_BUNDLE_IDENTIFIER = com.flutter.example;
Output App 2
[VERBOSE-2:ui_dart_state.cc(148)] Unhandled Exception: PlatformException(, App not found com.flutter.example, null)
#0 AppAvailability.checkAvailability (package:flutter_appavailability/flutter_appavailability.dart:40:9)