GLTFLoader camera follow mouse cursor

I wanted to make a nodding effect for my head figure like when I move my mouse at the upper right, my head figure will look up while looking sideways but I only make my head to face sideways, what should I do to in order to make it happen?

window.addEventListener('mousemove', function(e) {
    let percX = window.innerWidth*0.5 - e.clientX;
    camera.position.x = percX / 100;
    camera.lookAt(new THREE.Vector3(0,0,0));

You take into consideration only .clientX - which is the horizontal axis of the screen. To make the head look up and down (or, if I understand the code correctly, move the camera to the top-right of the head), you should also use mouse y position.