import { animate, utils, stagger } from 'animejs';

const [ $pauseButton, $alternateButton, $resumeButton ] = utils.$('.button');

const animation = animate('.square', {
  x: '17rem',
  ease: 'inOutSine',
  loop: true,
  delay: stagger(100),
});

const pauseAnimation = () => animation.pause();
const alternateAnimation = () => animation.alternate();
const resumeAnimation = () => animation.resume();

$pauseButton.addEventListener('click', pauseAnimation);
$alternateButton.addEventListener('click', alternateAnimation);
$resumeButton.addEventListener('click', resumeAnimation);

<div class="medium row">
  <div class="square"></div>
</div>
<div class="medium row">
  <div class="square"></div>
</div>
<div class="medium row">
  <fieldset class="controls">
    <button class="button">Pause</button>
    <button class="button">Alternate</button>
    <button class="button">Resume</button>
  </fieldset>
</div>