How to right-click upload files for analysis?

Hello!

I'm a semi new user of fortinet antivirus/web filtering (been using for about 4 months on about 3 different machines and I have a few samples that are not detected that I would like to upload for analysis. I have seen that you are supposed to be able to right-click and upload but everytime I try that It gives me the error "Failed to send" the file in the picture i've attached is a known clean file its just a test I did to get the error.

How do I go about fixing this so I can right-click upload? I have untinstalled/reinstalled multiples times.