How to load a link products for multi vendors for digital items

I need help I try to figure out how I can do this:
I have multi vendors store for digital items so sellers can sell digital items on my store but I don't want give them my FTP server if its possible somehow load a link on OC2 on product page so after buyer make a payment they can download digital products?
Seller use own server iclouds or FTP alternative and just put a link in product page