Students can use Panopto to record a video, share a video, or edit a video. Your professor can set up their assignments in a few different ways. They can provide a Panopto folder for you to upload your submission to, or ask that you set the correct sharing permissions on your video.
Using Panopto in Course Site
In Course Site, anywhere you see the text editor, you can use Panopto button.
The key is to ensure that your sharing permissions are correct. You need to verify that you are in the correct folder, or that your video has the correct sharing permissions.