Prefill: Using API or Zapier to prefill the form

Would it be possible to pipe customer data into jotform via API or ZApier to create the links instead of manual uploads?

Please note that you can already use API to store submissions to your forms. You can save the submission to your form, and then prefill your form using Tables or another form.

You can read more here:
https://api.jotform.com/docs/

Let us know if you have any additional questions.