Best practice to build JSON and send to another app?

I'm using WeWeb to collect a bunch of data that creates records across several tables. What is the best practice to create a JSON file that would then get sent to another app? I do want to store the JSON file for archiving. It's being sent to a PDF creator.

Is this normally done using the function stack? Just not sure how to trigger it? I used AirTable as my MVP and I use a formula field to build the JSON and then use Make to send to the PDF app using a webhook. I know I could use Make to retrieve the data from Xano, build then build the JSON, but pretty sure it be more efficient to do it in Xano.