Camera USB

am new to using Swift for a Mac Application. I am trying to control an external UVC-compliant camera focus and other capabilities. However, I'm having trouble with this and don't know where to start. I have downloaded an application from the App Store and it can control the focus and other capabilities.

I've tried IOKit but this seems to be complicated and this does not return any capabilities or control the camera.

I also tried AVfoundation and was able to open the camera, but using the following code did not work for me. as a device.isFocusPointOfInterestSupported returns false and without checking the app crashes.

@IBAction func focusChanged(_ sender: NSSlider) { do { guard let device = videoDevice else { return }

    try device.lockForConfiguration()
    
    // Check if focus mode and point of interest are supported
    if device.isFocusModeSupported(.locked) {
        device.focusMode = .locked
    }
    
    if device.isFocusPointOfInterestSupported {
        // Map the slider value (0.0 to 1.0) to the focus point's X coordinate
        let focusX = CGFloat(sender.doubleValue)
        let focusPoint = CGPoint(x: focusX, y: 0.5) // Y coordinate is typically 0.5 (centered vertically)
        device.focusPointOfInterest = focusPoint
    } else {
        print("Focus point of interest is not supported on this device.")
    }
    
    device.unlockForConfiguration()
    
    // Log focus settings
    print("Focus point: \(device.focusPointOfInterest)")
    print("Focus mode: \(device.focusMode.rawValue)")
} catch {
    print("Error adjusting focus: \(error)")
}

Any help or advice is much appreciated.