SOURCE

var box = document.getElementById("box")

// Setup the animation loop.
function animate(time) {
    requestAnimationFrame(animate);
    TWEEN.update(time);
}
requestAnimationFrame(animate);

var coords = { x: 0, y: 0 }; // Start at (0, 0)
var tween = new TWEEN.Tween(coords) // Create a new tween that modifies 'coords'.
        .to({ x: 300, y: 200 }, 1000) // Move to (300, 200) in 1 second.
        .easing(TWEEN.Easing.Quadratic.Out) // Use an easing function to make the animation smooth.
        .onUpdate(function() { // Called after tween.js updates 'coords'.
            // Move 'box' to the position described by 'coords' with a CSS translation.
            box.style.setProperty('transform', 'translate(' + coords.x + 'px, ' + coords.y + 'px)');
        })
        .start(); // Start the tween immediately.

<div id="box" class="box"></div>

.box{
  background:yellowgreen;
  width:100px;
  height:100px;
  
}