How do I attach a file to an assignment?

How do I attach a file to an assignment?

Some assignments allow you to attach a file via dropbox, google drive, or directly from your computer. To do so, choose how you would like to upload the file and then locate the file in the chosen drive (Google, Dropbox, etc). 
Once you add the document into the assignment, you'll need to click the upload button. 

You should then see the complete with a checkmark to notify you it is attached:


After that you'll use the bottom submit button and get this pop up


If everything is uploaded and attached, you'll end up at this screen.