Here's a solution to that annoying "You Need Permission" issue with Google Drive.
AnyoneCanView Chrome extension. When you are in a Google Doc, Slide, or Form, just click on the extension and with a single click--voila--the permission changes from "private" to "anyone with the link can view." Without the extension, this is a nine-click process. We teachers get used to it, but it is difficult for some of our students to remember all the steps. Have your students install this Chrome extension so they can change the permissions before uploading it to an external digital portfolio. (We use Seesaw and if the Drive permissions are not set correctly, parents cannot see the work they've uploaded.)