We use a service called OCLC Worldshare to fill ILL requests, and often, you will get an email from them with a link and a case sensitive password that lets you download the PDF of your requested article. The password is right below that link!
Why am I being asked for a password to get an ILL?
When I click on the link in the email to access my Interlibrary Loan, it asks me for a password.