We show the number of remaining prizes in the dashboard, and it is also possible to add-delete products.
We do not show this number in the app, though.
To see this number: open the campaign configuration, and go to step 3. Prizes. The number is shown in the field "Remaining prizes".
If you need to edit this number, enable the Edit mode ON, and you will see the field "Adjust number of available prizes". Add a positive or negative number to add or remove prizes to a live game.