Sprint projects provide workboards with columns that translate to burndown charts and add story points to Maniphest tasks.
The workboard for such a sprint project is supposed to function so that the development team can pick tasks from the backlog and move them through stages "Doing", "Review" and ultimately end up with "Done".
For this to be allowed however, it seems that the development team members need permissions to edit the project -- in this case the sprint project itself -- along with all its metadata.