SOURCE

const up = document.querySelector('.btn-top');
const down = document.querySelector('.btn-bottom');
const test = document.querySelector('.chunk');
up.addEventListener('click', function() {
  test.scrollIntoView(true);
});
down.addEventListener('click', function() {
  test.scrollIntoView(false);
});

<div class="chunk"></div>
<div class="btn-top">up</div>
<div class="btn-bottom">down</div>

body {
  height: 200vh;
}

.chunk {
  margin-top: 100vh;
  height: 20vh;
  background: lightcoral;
}

div[class^=btn] {
  width: 50px;
  padding: 10px 15px;
  position: fixed;
  top: 50vh;
  right: 0;
  border-radius: 10px;
  cursor: pointer;
  text-align: center;
}

.btn-top {
  background: lightgreen;
}

.btn-bottom {
  margin-top: 50px;
  background: lightblue;
}