I'm currently trying to animate a few frames from a spritesheet using Phaser3. The page successfully renders the first frame of the animation to the screen, but fails when I try to actually code in any of the animations.

Here's what I have so far:

export default class Intro_Animation extends Phaser.Scene
{
  constructor()
  {
    super('Intro_Animation');
  }

  intro(){}

  preload()
  {
    this.load.path = './src/assets/intro/';

    this.load.spritesheet('intro_frame', 'westwardJourney_02-Sheet.png',
  {frameWidth: 144, frameHeight: 130});
  }

  create()
  {
    //fails somewhere in the animations here
    var introAnim_config = {
        key: 'introWalkAnim',
        frames: this.anims.generateFrameNumbers('intro_walk', { start: 0, end: 23, first: 23 }),
        frameRate: 20,
        repeat: -1
    };

    this.anims.create(introAnim_config);

    //loads in first frame here
    this.add.sprite(250, 150, 'intro_frame').play('introWalkAnim');
  }
}