Quickstream API and PHP iframe set up

***Please don't bid or message unless you've read the docs below.

Needing to set up APIs using Westpac's Quickstream platform. Setting up an iframe solution using their off-the-shelf code. Full documentation and access provided. For now, details include:

API Documentation and steps are on: https://quickstream.westpac.com.au/docs/quickstreamapi/v1/

Link to .js scripts: https://quickstream.westpac.com.au/docs/quickstreamapi/v1/quickstream-api-js/#quickstream-api-js-reference

That needs to display within an iframe on a Wordpress page.

Additional API key info:

https://quickstream.westpac.com.au/docs/quickportal/administration/#manage-rest-api-keys

"REST API Toolbox": https://quickstream.westpac.com.au/docs/quickstreamapi/
From the menus, 'Developers' -> 'Summary' gets you back to this page.

The "Trusted Frame and Custom Form" page: https://quickstream.westpac.com.au/docs/quickstreamapi/v1/trusted-frame-and-custom-form/

The API Reference: https://quickstream.westpac.com.au/docs/quickstreamapi/v1/#api-reference