Assign new String

Hi, I’m about to playing around with plugin development in Figma. I tried to change the value of a textNode on click. The values are stored in a simple array.

So I have an array and a random calc to replace the textNode with other values if button is hit again:

var names = ["John", "Elias", "Mark", "Robert", "Niels", "Andrea"];
var randomItem = names[Math.floor(Math.random() * names.length)];

here’s the html side:

<button id="runPlugin">Change Text</button>
<script>
  document.getElementById("runPlugin").onclick = () => {
    const text = document.pluginMessage.selection();
    parent.postMessage({ type: { request: "runPlugin" } }, "*");
  };
</script>

on the .ts side I’m having a bit trouble. I made sth similar in js which is working but this… 🤯I know I’m doing sth really wrong in the 2nd if section…

figma.ui.onmessage = async (event) => {
  if (event.type === "request:runPlugin") {
    let selection = figma.currentPage.selection[0];
    if (selection) {
      selection = event.randomItem;
    }
    return;
  }

Any idea? Thanks!