Bit of a work-around using a module for something it's not meant for, but this a way you could achieve it:
Try using Quiz instead as this allows for automatic marking.
- Use whatever Scale you want to use.
- Deselect everything under Review options.
- Change total marks to "1"
- Add an Essay question, which will be unmarked.
- Set Mark to "0"
- Set Response format to "No online text"
- Set both Allow attachments and Require attachments to "1" (or however many files they need to upload).
- Add a multiple choice question, which can be any question you want to add (for example a "I haven't plagiarised" statement). This question is marked, which will add the points to your Gradebook.
- Set Mark to "1"
- Set One or multiple answers to "Multiple answers allowed
- Deselect "Shuffle choices"
- Add two answers and set the Grade to "50%" for each (one answer doesn't work for a multiple choice question).
The multiple choice question will be automatically marked.