I need to connect my cms to my member page

I’m having trouble with

A CMS. I had to create a form from scratch that would accept domestic vs international shipping because shipping cost are dependent on location and number of product ordered. now im fiding out that the data is not the right one and that its not creating the invoices.

Working in
Wix Studio Editor, Wix Editor, Dev Mode, CMS,

What I’m trying to do

I want it to use all the info submitted on the form to use as the members information. I also want it to use that info to create Invoices.

What I’ve tried so far

I wrote code in Velo that would calculate all that. then i connected it to a cms so that we could create invoices based on the submissions. Im just at a loss.

Extra context
Anything else that might help - edge cases, screenshots, etc.