Get PDF file from Cold Fusion to mobile app

Hello, we are working on the mobile app for the store. The ERP software use Cold Fusion to generate PDF the invoice for customer. But ERP database do not store the PDF file. 

The challenge is we need to send PDF invoice to customer mobile app, like the proven date of purchase and start the warranty period from the date of invoice. 

Anyone help us to know how to get the PDF after Cold Fusion done in ERP and put it into customer mobile app?