Движение объекта по picturebox кнопками

 private static Bitmap myBitmap = new Bitmap(750, 150);
        private Graphics myGraphic = Graphics.FromImage(myBitmap);
        private Pen boardPen = new Pen(Color.Azure, 1);
        private Pen contour = new Pen(Color.Black, 1);
        private static int movingCoef = 0;
        private Rectangle board = new Rectangle(10+movingCoef, 100, 70, 10);
 
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            myGraphic.DrawRectangle(contour, board);
            myGraphic.FillRectangle(new SolidBrush(Color.Aquamarine), board);
            pictureBox1.Image = myBitmap;
        }
 
        private void Form1_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Left)
            {
                movingCoef -= 1;
                Invalidate();
            }
            if (e.KeyCode == Keys.Right)
            {
                movingCoef += 1;
                Invalidate();
            }
        }

private Pen contour = new Pen(Color.Black, 1);
private Rectangle board = new Rectangle(10, 100, 70, 10);
 
public Form1()
{
    InitializeComponent();
}
 
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
    e.Graphics.DrawRectangle(contour, board);
    e.Graphics.FillRectangle(new SolidBrush(Color.Aquamarine), board);
}
 
private void Form1_KeyUp(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.Left)
    {
        board.Offset(-1, 0);
        pictureBox1.Invalidate();
    }
    if (e.KeyCode == Keys.Right)
    {
        board.Offset(1, 0);
        pictureBox1.Invalidate();
    }
}

bool isStarted;
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
    if (!isStarted) return;
    e.Graphics.DrawRectangle(contour, board);
    e.Graphics.FillRectangle(new SolidBrush(Color.Aquamarine), board);
}