It is a must have that the user receive an invoice by email or downloaded à PDF invoice when purchased with a subscription ProSites.
Actualy there bis only one receip send by mail, but it is not an legal invoice with
A seller must have the possibillyty to donwload / export all the invoice too.
This is the law in european country.
I dont undurstand why the is not this feature in pro site... it's a good pluggin but it's like he is not finished