Use the Embedded option of publishing to add the verification form as an embedded iframe within a page you host
See this example: https://offers.sheerid.com/demo-bank-military/#/
The iframe is auto-sized. While the iframe is typically a set width, different consumer segments and different steps in the verification journey will use different form heights.
For more control, such as fixing a max height of the iframe, add css styles to the iframe element, such as “max-height”. This will make the iframe scroll within the container.