如何将此Javascript代码转换为Phaser代码？

// 原始Javascript代码
var canvas = document.getElementById("gameCanvas");
var context = canvas.getContext("2d");

function drawCircle(x, y, radius) {
  context.beginPath();
  context.arc(x, y, radius, 0, 2 * Math.PI);
  context.fillStyle = "red";
  context.fill();
}

canvas.addEventListener("click", function(event) {
  var x = event.clientX;
  var y = event.clientY;
  drawCircle(x, y, 50);
});

// 转换为Phaser代码
var config = {
  type: Phaser.AUTO,
  width: 800,
  height: 600,
  scene: {
    create: create
  }
};

var game = new Phaser.Game(config);

function create() {
  var graphics = this.add.graphics();
  
  function drawCircle(x, y, radius) {
    graphics.fillStyle(0xff0000);
    graphics.fillCircle(x, y, radius);
  }
  
  this.input.on("pointerdown", function(pointer) {
    var x = pointer.x;
    var y = pointer.y;
    drawCircle(x, y, 50);
  });
}