Selection.serialize()

import { parseHTML } from 'k6/html';
import { sleep } from 'k6';

export default function () {
  const content = `
 <form><input name="username"></form>
  `;

  const doc = parseHTML(content);
  const sel = doc.find('form');
  const serialized = sel.serialize();

  console.log(serialized); // "username="

  sleep(1);
}