How do you make a from filled out ties to an employee file?

How do you make a from filled out ties to an employee file?

I'm trying to make it so employees can upload their own files through a form since a lot of our employees work nationwide at home. How can I make it so if they fill out a new form that I created, that it will tie to their employee account automatically? I need employees to fill out multiple forms which tie to their employee account.