Ticket Tuesday not working

Hello. I'm trying to buy tickets under the ticket tuesday promotion in the app, but it isn't working. I'm receiving an error. I tried uninstalling and reinstalling the app, but it isn't working. How do I get this fixed as I would like to see a movie this evening. This is also the first time I've used ticket tuesday since it moved solely into the app. I prefer to use the desktop version of this, so would be great if that could be brought back.