How to create Zoho Invoice for a paid order

How to create Zoho Invoice for a paid order

Hi,

I am new to Zoho. I am using Wix for my ecommerce site. I want to know how to generate an invoice for an order thats already paid through Wix site? Under invoice in Zoho I see Terms where it gives options like Due on receipt or Net 15 etc. Shall I create a new one and say Net 0, will that help. Please advice.