Create a Voice-Isolating Video Call App with SwiftUI

The Agora Extensions Marketplace, launched in September 2021, offers several extensions for enhancing video call apps. One such extension is Bose PinPoint, which helps remove background noise from calls. To integrate this extension into an existing iOS app using SwiftUI and Agora UIKit, developers need to follow a few steps: 1. Enable the extension by calling `AgoraVideoViewer.enableExtension()` with the appropriate vendor and vendor extension parameters. 2. Add the PinPoint extension via the Swift Package Manager using the URL https://github.com/AgoraIO-Community/Extension-Bose-PinPoint-iOS.git. 3. Define a method to register the PinPoint API Key and API Secret with the extension using `AgoraViewerHelper.agview.viewer.setExtensionProperty()`. 4. Add a button to toggle the extension on or off, updating the background color accordingly. By following these steps, developers can create an enhanced video call app that effectively removes background noise for improved user experience. Other extensions available in the Agora Extensions Marketplace can also be integrated into apps made directly with the Agora SDK.