我正在使用GameObjectFactory注册myPlayer

import Phaser from 'phaser'
import Player from './Player'
import { Direction } from '@/types/phaser';

export default class MyPlayer extends Player {
  constructor(
    scene: Phaser.Scene,
    x: number,
    y: number,
    defaultDirection: Direction
  ) {
    super(scene, x, y, defaultDirection)
    scene.add.existing(this)
  }
}

declare global {
  namespace Phaser.GameObjects {
    interface GameObjectFactory {
      myPlayer(x: number, y: number, defaultDirection: Direction): MyPlayer
    }
  }
}

Phaser.GameObjects.GameObjectFactory.register(
  'myPlayer',
  function (
    this: Phaser.GameObjects.GameObjectFactory,
    x: number,
    y: number,
    defaultDirection: Direction
  ) {
    const sprite = new MyPlayer(this.scene, x, y, defaultDirection)

    this.displayList.add(sprite)
    this.updateList.add(sprite)

    return sprite
  }
)

我尝试在场景中使用this.add.myPlayer

import Phaser from 'phaser'
import MyPlayer from '@/players/MyPlayer'
import { CustomCursorKeys } from '@/types/phaser'
import { Direction } from '@/types/phaser'

export default class BaseScene extends Phaser.Scene {
  public cursors: CustomCursorKeys | null = null
  public myPlayer: MyPlayer | null = null

  constructor(key: string) {
    super(key)
  }

  create(param: { 
    map: Phaser.Tilemaps.Tilemap, 
    x: number, 
    y: number, 
    direction: Direction 
  }) {
    console.log('this.add.myPlayer', this.add.myPlayer)
    this.myPlayer = this.add.myPlayer(705, 500, 'up')
  }
}

但是this.add.myPlayer控制台记录为undefined。我做错了什么？