<div class="container">
    <div class="square"></div>
    <div class="square red"></div>
    <div class="square yellow"></div>
    <div class="square purple"></div>
    <div class="square black"></div>
    <button class="animButton">Click to animate</button>
  </div>

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.container {
  width: 100%;
  height: 100vh;
}

.square {
  width: 50px;
  height: 50px;
  background-color: blue;
}

.red {
  background-color: red;
}
.yellow {
  background-color: yellow;
}
.purple {
  background-color: purple;
}
.black {
  background-color: black;
}

const animButton = document.querySelector(".animButton")
animButton.addEventListener("click", animateOnClick)
function animateOnClick(){
  gsap.to(".square", { duration: 1, x: 200, stagger: 0.15})
}