Wordpress/Gravity Forms - transfer entry data through API

We are using Gravity Forms for our registration system and have two tasks:

The form is here: https://tinyl.io/5gvi

1. Fix error 'Jquery is not defined'
- When going to a new page on our form we get a console error "Uncaught ReferenceError: jQuery is not defined"
- This is from custom javascript we are using to make two of the fields readonly
- Can find the related on in: child theme/functions.php ~line 2062
- The script is working, but this error is showing up each time the user goes to the next page
- We want to eliminate the error, but make sure the script still works and makes the fields 'readonly'

2. Push data for existing entries to CMS
- We use a Customer Management System called FreeAgent to store data after a user submits the registration form. We use an API to push the data from Gravity Forms to the CMS.
- We recently added a new field to the CMS called "Registration Date." This field is being pushed over for new registrations, but we want to also update the existing entries.
- There are about 2,000 existing entries that need to have the registration date synced.
- Write a PHP script to loop through the existing entries for form "Spring 2022 Registration" and push the date of the form submission to FreeAgent: Player > Registration Date (player_field47)
- I can provide sample code for the API used to update the entry
- Script should:
> loop through all existing entries
> identify each child that was registered (each form can register up to 5 children)
> Look up the child in FreeAgent based on their Name and Date of Birth. (our existing code already does this, check that code for example)
> Update the record in FreeAgent with the Registration Date (player_field47) of when the form was submitted

This is a live site, so please be cautious not to effect current users.