restart

html,
body,
svg {
  height: 100%;
}

a {
  fill: blue;
  text-decoration: underline;
  cursor: pointer;
}

<svg viewBox="0 0 220 200" xmlns="http://www.w3.org/2000/svg">
  <rect y="30" width="100" height="100">
    <animate
      attributeType="XML"
      attributeName="y"
      from="30"
      to="100"
      dur="5s"
      repeatCount="1"
      restart="always" />
  </rect>
  <rect x="120" y="30" width="100" height="100">
    <animate
      attributeType="XML"
      attributeName="y"
      from="30"
      to="100"
      dur="5s"
      repeatCount="1"
      restart="whenNotActive" />
  </rect>
  <a id="restart"><text y="20">Restart animation</text></a>
</svg>

document.getElementById("restart").addEventListener("click", (evt) => {
  document.querySelectorAll("animate").forEach((element) => {
    element.beginElement();
  });
});