Hi Syed,
Sorry for the late response, we were on a family vacation, it was announced on the site header.
I have found the issue. The theme functions are de-queueing the jQuery script, and therefore the plugin script files are not loaded: https://i.imgur.com/N0cEgBu.png
I would highly recommend recommed leaving the jQuery enqueued by WordPress, as almost every plugin on the market uses it as a pre-requesite. Removing that line should very likely resolve the issue immediately.