Need to add JS to a button

First and foremost, I am a coding noob. So any help is greatly appreciated, I am thankful for a forum such as this one.

Currently, I need to add this script to a button in order to enable cross-domain tracking on a site that connects to a Acuity Scheduling sub-page:

<script src="https://embed.acuityscheduling.com/embed/button/22619547.js" async></script>

I am looking to add it to all “Book Now” buttons. Some have different classes than other but once I figure this out I think I’ll be able to apply to each button class.

Thank you to ANYONE who can help.


READ ONLY Link to site: https://preview.webflow.com/preview/forward-detailing?utm_medium=preview_link&utm_source=designer&utm_content=forward-detailing&preview=f6382183498c0f73d96bde560693b040&workflow=preview