Issue: Platform Implementation Not Set for flutter_inappwebview on macOS and Windows

[priyankvirani]

I am encountering the following error when using the flutter_inappwebview package in my Flutter project targeting macOS and Windows:

A platform implementation for flutter_inappwebview has not been set. Please ensure that an implementation of InAppWebViewPlatform has been set to InAppWebViewPlatform.instance before use. For unit testing, InAppWebViewPlatform.instance can be set with your own test implementation.
'package:flutter_inappwebview_platform_interface/src/in_app_webview/platform_inappwebview_widget.dart':
Failed assertion: line 202 pos 7: 'InAppWebViewPlatform.instance != null'

Steps to Reproduce:

• Add flutter_inappwebview as a dependency in pubspec.yaml.
• Create a simple widget that uses InAppWebView.
• Build and run the Flutter project on macOS or Windows.
• Observe the error message in the console.