Rest API – API POST to Quickbooks with OAuth

I've created a form on my website that the customer can fill in, and I want to use that data to create a customer in Quickbooks.
I have the JavaScript API code that works in vs code with node.js, but I'm not sure how to transfer that code to my website.

I upload to cpanel and call php,
Should I use Ajax / jquery or WP Rest API?
I'm completely wrong: S
I'm not even sure how to string a matching Google together.

Thank you very much!!