How to set up button code to pop up 3rd party form?

Hello!

I am trying to add a button my SS7.1 site, which would trigger a pop-up form, sending info to a 3rd party service we utilize.  The (very brief) instructions from the app developer are as follows:

To add a referral form to your website:
1. Copy this code into the HTML head on your webpage:
<script src="https://app.vpop-pro.com/referral.js?emailId=p8owrmk71ts2"></script>
2. Add a button with the an id: VPOPReferralButton
<button id="VPOPReferralButton">Refer a patient</button>

The header script is the easy part, but I don't understand how to add the button with ID, so that it pops up the form "OVER TOP" of the page content.  Can you assist?

@JewelVS Hi! Can you share your website URL for context? Also, let me know which button you'd like to use to trigger the popup form.

Hi Lesum,

https://www.jewelvs.com/submit-a-case

That worked. Thank you!