HubSpot doesn’t support custom elements, so you will have to use our compatibility mode version of the embed code in place of the normal embed code.
How to Set Up Compatibility Mode
Use the compatibility mode embed snippet below, and swap out the spiffy URL for the checkout you are embedding.
Compatibility Mode
<div class="spiffy-checkout__container" data-url="https://example.spiffy.co/checkout/my-checkout"></div>
Learn more about compatibility mode in our developer documentation.