Wordpress/Gravity Forms custom code needed - Push data to API after form submission

We have a Wordpress form built in Gravity Forms and we need to integrate it with our customer management system. After a user successfully submits the form we need to use an API to push that data to our CMS system. I have extensive documentation on the API and have examples of it being used previously. The API is using GraphQL. Project requirements are below: 1. When the user successfully submits the form (only after successful payment) there are about 50 fields that need to be pushed to the CMS through their API. 2. Most fields will be creating new entries, but some will need to check for an existing entry and update it if found. 3. I will provide an Excel doc with the detailed list of mappings, but an outline is below: Parent info - maps to 'contact' in the CMS - Wordpress user account has a custom field 'freeagent_id' which is used to find a matching record in the CMS - If no matching account is found then add a new entry instead of updating - Sync these fields: Primary email, Secondary email, Primary Cell Number, Secondary Phone Number, How Many children will be signing up? - 'Season' is not on the form, but will always push the value 'Summer 2020' to the CMS Child Info - maps to 'player' in the CMS - The form allows entering up to 3 children, for each child entered on the form perform the following: - Check if the 'player' already exists by matching: first name, last name and date of birth - If a match is found update that record, otherwise enter a new 'player' - There are about 15 fields that will need to be synced Relational Fields - in our CMS the parents can be assigned to one or more 'players' so we know which players below to each parent. This is a unique field, but should also be updated so that players entered on the form are matched with the parent that registered them. 4. After the data has been correctly pushed to the CMS Wordpress would show the confirmation page as normal. 5. If there is an error with the API this should be logged somewhere for the administrator (can be a txt file on the server) and the user should see an error message letting them know there was a problem. I can provide links to our registration form, API documentation and other information for those interested. Thanks