There are several items to check. I used the guest login to your site and looked at the course.
- Are you certain you are logged in as the 'fake' student? In order to fully test an assignment upload you must login as a user who has the student role in a course - not using the 'Switch role to..' option.
- From your screenshot, it appears you clicked the 'Immigration' link in your course, which is a Moodle page, not an assignment. You need to click the 'Immigration essay' link, which is an assignment link.
- Is your Immigration Essay assignment configured for uploading of files? From the link I was able to use, it appears the assignment is configured as an offline assignment without the ability to upload files or enter online text. Go back and look at the assignment settings.
By the way.... I grew up in Lansdale, just south of Allentown. My in-laws lived in Bethlehem. I visited there many times.