Confirm the most recent printer driver update is installed to your Mac, and that the printer is turned on and plugged into your computer.

Open Printopia from your Applications

Select the printer you are using, and then open the settings from the right hand side of the page.

Select "Printer Features" from the dropdown menu

On the right side of this menu, you will see settings for the Cut Operation. Select "2 inch" and click OK

Make sure your iPad is properly connected to the printer and then try a test print, you should be good to go!