Phaser Sprite functions are undefined

Even though I can play animations in Phaser3 just fine, I can’t seem to use basic functions such as Sprite.playReverse() or Sprite.playAfterDelay. Using them produces the error “sprite.playAfterDelay is not a function”, which is strange because Visual Studio can trace to them. Here’s some of the code I think might be the issue:

  preload() {
        this.load.spritesheet('fullWalk', './src/assets/memble_anim/full_walk-Sheet.png', { frameWidth: 40, frameHeight: 64 });
        this.load.spritesheet('fire', './src/assets/memble_anim/fire-Sheet.png', { frameWidth: 32, frameHeight: 32 });
        this.load.image('background', './src/assets/memble_anim/tutorial_background.png');
 let intro_sprite = this.add.sprite(50, 220, 'fullWalk');
 const fireSprite = this.add.sprite(300, 260, 'fire');

 intro_sprite.playAfterDelay('_stepOne', 1000);

Could it be that intro_sprite isn’t loaded in as an Atlas? I’m quite lost and new to Phaser, so any extra eyes / help is greatly appreciated!

Check the Phaser version in the browser console. These functions are in Phaser v3.50 and later. How are you including Phaser itself?