Stamp Duty calculator.

<!-- Wilson Partners Stamp Duty calculator embed -->
<iframe
  id="wp-stampduty"
  src="https://wilson-partners-stamp-duty-calculator.lovable.app/?embed=true"
  title="Stamp Duty calculator"
  style="width:1px;min-width:100%;border:0;display:block;"
  loading="lazy"
  scrolling="no"
></iframe>
<script>
  (function () {
    var iframe = document.getElementById('wp-stampduty');
    if (!iframe) return;

    // Fallback listener — works even if the iframe-resizer CDN script is
    // delayed, lazy-loaded, or blocked. The embed page posts its height
    // continuously (on resize + on interval), so we can never miss it.
    window.addEventListener('message', function (event) {
      var data = event.data;
      if (!data || typeof data !== 'object') return;
      if (data.type === 'wp-calc:resize' && typeof data.height === 'number') {
        iframe.style.height = data.height + 'px';
      }
    });

    // Ask the embed for its current height once we're listening, in case it
    // already posted its first message before this script attached.
    var requestHeight = function () {
      try {
        iframe.contentWindow &&
          iframe.contentWindow.postMessage({ type: 'wp-calc:request-height' }, '*');
      } catch (e) {}
    };
    iframe.addEventListener('load', requestHeight);
    // Also poll briefly in case 'load' already fired.
    var tries = 0;
    var poll = setInterval(function () {
      requestHeight();
      if (++tries > 10) clearInterval(poll);
    }, 300);
  })();
</script>
<!-- Optional: also enable iframe-resizer for pixel-perfect sizing -->
<script src="https://cdn.jsdelivr.net/npm/@iframe-resizer/parent@5"></script>
<script>
  if (typeof iframeResize === 'function') {
    iframeResize({ license: 'GPLv3' }, '#wp-stampduty');
  }
</script>

Prefer a fixed height? Remove the <script> block and set the iframe's height attribute to a value that suits your layout (e.g. 1400).