<div class="container">
  <div class="row justify-content-md-center mt-5">
    <div class="col-6">
      <div class="card">
        <div class="card-body">
          <h5 class="card-title">Item external reference</h5>
          <p class="card-text">
            Click the button bellow to open the Inline Cart with an item external reference.
          </p>
          <a href="#" class="btn btn-success" id="buy-button">Buy now!</a>
        </div>
      </div>
    </div>
  </div>
</div>
window.document.getElementById('buy-button').addEventListener('click', function() {
  TwoCoInlineCart.setup.setMode('DYNAMIC');
  TwoCoInlineCart.cart.setCurrency('USD');
  TwoCoInlineCart.products.add({
    name: "A test dynamic product",
    price: 10,
    externalReference: 'test-item-external-ref'
  });
  TwoCoInlineCart.cart.checkout();
});

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.1.3/css/bootstrap.min.css

External JavaScript

  1. https://codepen.io/2checkout-documentation/pen/PrPdqb