How to prefill Tockify fields?

I currently use Auth0 (SPA JS - https://github.com/auth0-samples/auth0-javascript-samples/tree/master/01-Login) to log users in, and then once logged in the user can view my calendar that is from Tockify:

<div data-tockify-component="mini" data-tockify-calendar="myCalendar"></div>
<script data-cfasync="false" data-tockify-script="embed" src="https://public.tockify.com/browser/embed.js"></script>

Once a user clicks on an event a pop-up appears, and they then can click RSVP which creates another pop-up.

Here I can choose to include fields like Email and Name.

I would like to know how to pre-fill these fields with the details from Auth0 as the users are already logged in.

I have tried a variety of methods but not sure how to go about this.

The Tockify API adds an iframe and I am trying to get the below code to work:

JQuery - prepopulate form field on 3rd party form

Thanks for any insight in advance.