The D2L Dropbox folder is an assignment submission folder where students upload completed assignments such as document, graphic, audio, and video, files. A separate Dropbox folder is required for each assessment item submission. Each Dropbox needs to be associated with Gradebook assessment items in order to transfer grades assigned in the Dropbox to Gradebook.
How to Setup a Dropbox?
Refer to the following link to access print and video guides for setting up your course Dropbox: "How to Setup D2l Dropbox"