Disabling necessity to log in in order to download ready-print file

Hello,

we use a script which saves files into Google Drive folder. It is tailored to our needs and it gets around the problem with Woocommerce Composite Products, which is not compatible with FPD. 

Recently our script doesn't work, because now the user need to be logged into Wordpress in order to download files via link like https://xxxx.com/?fpd_download=wc&fpd_order_id=XYZ&fpd_item_id=ABC

Because of that we need to search and download all the files manually from the Dropbox.

How can we disable the necessity to log in to Wordpress to download the ready-print files?