Howdy @bmaestas ,
In order to submit multiple files to an assignment, you would follow this helpful guide:
How do I submit an online assignment?
On that page, you'll notice the "submit file upload" section.
On that image you'll see "choose file" to upload your first, but right underneath there is "+Add another file" ... basically use that "+Add another file" option to submit your next file upload before clicking on the "Submit Assignment" button.
Hope this helps,
Sky V.
