Custom Track & Trace Embed Won't Work in Webflow?

I have a shipping ‘track & trace’ element that has been provided to me to place in an embed on a website. The code functions as expected on its own hosted server. However when inserted into Webflow the ‘track’ buttons don’t call the popup modal to function as intended.

Here is my Webflow with the embed: Embed Problem

Here is the code on its own server: Embed Original

Does anyone have an idea as to why this wouldn’t function on the Webflow site?

Here is my site Read-Only: (Webflow - DELETE ME)
(how to share your site Read-Only link)