How can I implement touch control to my ping pong game?

I want to add touch controls when the game is played on touch screen devices , Ideally, the user paddle would move every time I touch the screen. Here is the code I have inputted for my key presses.

window.addEventListener(‘keydown’, keyDownHandler);
window.addEventListener(‘keyup’, keyUpHandler);

function keyDownHandler(event) {
  switch (event.keyCode) {
    case 38:
        upArrowKey = true;
        break;
    case 40:
        downArrowKey = true;
        break;
}
}

function keyUpHandler(event) {
  switch (event.keyCode) {
    case 38:
        upArrowKey = false;
        break;
    case 40:
        downArrowKey = false;
        break;
}
}

And this is the code that I inputted to move the ball if user presses key.

let userSpeed = 9;
if (upArrowKey && user.y > 0) {
 user.y -= userSpeed;
}else if (downArrowKey && (user.y < canvas.height - user.height)) {
 user.y += userSpeed;
}

How can I implement touch controls in the same way?