Events Ticket Plus and JQuery

I recently was able to get the non-profit version of Event Ticket Plus so that our organization can register people and collect the Attendee information.

Unfortunately if you go to the link: https://www.ppcc-pa.org/event/4th-annual-pediatric-palliative-care-coalition-conference/

You will see that when you select the amount greater than 1, NO ATTENDEES information collection shows up.

Now I realize we have an outdated custom template that was made a few years back. The problem revolves around JQUERY. I’ve ran a plugin called “jQuery Updater”. This FIXED the problem. However, it caused our navigational menu to no longer do dropdown menus. When I deactivate the plugin everything works again except the Attendee information.

I’ve gotten these errors in the Google console:
Uncaught TypeError: t(…).on is not a function
at frontend-ticket-form.min.js?ver=4.7.3.1:1
at frontend-ticket-form.min.js?ver=4.7.3.1:1
events-manager.js?ver=5.93:165 Uncaught TypeError: $(…).on is not a function
at HTMLDocument.<anonymous> (events-manager.js?ver=5.93:165)
at Object.resolveWith (jquery-1.6.4.min.js?ver=1.6.4:2)
at Function.ready (jquery-1.6.4.min.js?ver=1.6.4:2)
at HTMLDocument.C (jquery-1.6.4.min.js?ver=1.6.4:2)

I believe that may be the key to fixing the issue, but I am not familiar with it at all.

Has anyone fixed Jquery issues and conflicts?

The page I need help with: [log in to see the link]