How to run SkeletalAnimation through script?

I am new to CocosCreator. I have an exported fbx model from Maya tool. After I imported it to CC I could see a prefab with cc.SkeletalAnimation as the image below.
image
I also have a script attached to the prefab but nothing happens after I click. How can I achieve it?

@ccclass('MermaidController')
export class MermaidController extends Component {
    private _startAnim: boolean = false;
    private _animation: SkeletalAnimation | null = null;

    protected onLoad(): void {
        this._animation = this.node.getComponent(SkeletalAnimation);
    }

    start() {
        input.on(Input.EventType.MOUSE_UP, this.onMouseUp, this);
    }

    update(deltaTime: number) {
    }

    onMouseUp(event: EventMouse) {
        if(event.getButton() === EventMouse.BUTTON_LEFT) {
            console.log('start anim: ' + this._startAnim);
            this._startAnim = true;
            this._animation?.start();
            console.log('start anim: ' + this._startAnim);
        }
    }
}

The command to run animation is this._animation?.play(name_of_animation_clip);. I found it in this tutorial for the old version 3.2 https://docs.cocos.com/creator/3.2/manual/en/engine/animation/animation-component.html. I wonder where is the doc for manual programming for Creator 3.8