Rounding the drawn line(path) with flutter custom painter

I have below custom painter and I want to round any edge of the path

I will be grateful if you help

you can use this CustomPainter:

class CustomDraw extends CustomPainter {
  late Paint painter;
  late double radius;

  CustomDraw(Color color, {this.radius = 0}) {
    painter = Paint()
      ..style = PaintingStyle.stroke
      ..strokeWidth = 10
      ..strokeCap = StrokeCap.round
      ..color = color;
  }

  @override
  void paint(Canvas canvas, Size size) {
    var path = Path();

    path.moveTo(size.width, 0);
    path.lineTo(0 + radius, 0);
    path.cubicTo(0 + radius, 0, 0, 0, 0, radius);
    path.lineTo(0, 35 - radius);
    path.cubicTo(0, 35 - radius, 0, 35, radius, 35);
    path.lineTo(size.width - radius, 35);
    path.cubicTo(
        size.width - radius, 35, size.width, 35, size.width, 35 + radius);

    path.lineTo(size.width, 35 + 35 - radius);

    path.cubicTo(size.width, 35 + 35 - radius, size.width, 35 + 35,
        size.width - radius, 35 + 35);

    path.lineTo(0, 35 + 35);

    canvas.drawPath(path, painter);
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) => false;
}

use it like this:

CustomPaint(
    painter: CustomDraw(Colors.red, radius: 16),
    child: SizedBox(
      height: 100,
      width: 200,
    ),
  ),