How to color a bezier path with gradient

Question

I have a class to draw bezier path.

class CircularProgressView: UIView {

public var radius: CGFloat = 66

private var isClosed = false

private var customProgressColor: UIColor?
private var customCircleColor: UIColor?

private var lineWidth: CGFloat?
private var progressWidth: CGFloat?

private var circleLayer = CAShapeLayer()
private var progressLayer = CAShapeLayer()

private override init(frame: CGRect) {
    super.init(frame: frame)
}

public convenience init() {
    self.init(frame: .zero)
    translatesAutoresizingMaskIntoConstraints = false
    createCircularPath()
}

public convenience init(progressColor: UIColor, circleColor: UIColor, isClosed: Bool, radius: CGFloat, lineWidth: CGFloat = 3, progressWidth: CGFloat = 6) {
    self.init(frame: .zero)
    translatesAutoresizingMaskIntoConstraints = false
    
    customProgressColor = progressColor
    customCircleColor = circleColor
    
    self.isClosed = isClosed
    self.radius = radius
    self.lineWidth = lineWidth
    self.progressWidth = progressWidth
    
    createCircularPath()
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

public func createCircularPath() {
    var circularPath = UIBezierPath(arcCenter: CGPoint(x: radius, y: radius), radius: radius,
                                    startAngle: 2.5 * -.pi / 2,
                                    endAngle: .pi / 3.5,
                                    clockwise: true)
    
    if isClosed {
        circularPath = UIBezierPath(arcCenter: CGPoint(x: radius, y: radius), radius: radius,
                                    startAngle: -.pi / 2,
                                    endAngle: .pi * 1.5,
                                    clockwise: true)
    }
    
    circleLayer.path = circularPath.cgPath
    circleLayer.fillColor = UIColor.clear.cgColor
    circleLayer.lineCap = .round
    circleLayer.lineWidth = lineWidth ?? 10
    circleLayer.strokeColor = customCircleColor == nil ? UIColor.white.withAlphaComponent(0.3).cgColor : customCircleColor?.cgColor
    
    progressLayer.path = circularPath.cgPath
    progressLayer.fillColor = UIColor.clear.cgColor
    progressLayer.lineCap = .round
    progressLayer.lineWidth = progressWidth ?? 10
    progressLayer.strokeEnd = 0.0
    
    progressLayer.strokeColor = customProgressColor == nil ? UIColor.white.cgColor : customProgressColor!.cgColor
    
    layer.addSublayer(circleLayer)
    layer.addSublayer(progressLayer)
}

public func progressAnimation(duration: TimeInterval, value: Double) {
    let circularProgressAnimation = CABasicAnimation(keyPath: "strokeEnd")
    circularProgressAnimation.duration = duration
    circularProgressAnimation.toValue = value
    circularProgressAnimation.fillMode = .forwards
    circularProgressAnimation.isRemovedOnCompletion = false
    progressLayer.add(circularProgressAnimation, forKey: "progressAnim")
}

}

I need to color the progress of the circle into a gradient

enter image description here

I found a possible solution How to fill a bezier path with gradient color . But I don't understand how to apply it to my problem.

Help me, please.