How do I send a link to a customer to upload an attachment and have it go to the IO attachment list?

Cindy B. shared this question ago

Need Answer

I've looked through the variable and don't see one listed (except to view a list of attachements already received). I want to send a link in an email to the customer to upload an attachment that we require (tax exempt certificates, drivers licenses, etc) and have it go to their lead in the attachment section.