UR12 not connecting to ipad

Being interested in recording cigar box guitar/ keyboard syntheses, I was recommended to buy a UR12 to interface with recording/mixing software on my iPad (6th gen 2018 running iOS 12.1). However, I cannot get it to connect with the iPad at all. I’ve got the 5v input working, but despite having the correct camera-connection kit there is no output to Cubase, or ToneStack, or GarageBand, or anything. The connection kit has worked with a midi keyboard, and I’ve played guitars through an iRig, so it’s not the lightning. The only sound I can get is a clean tone through headphones- clearly not via the iPad. The manual keeps banging on about the correct software- but that’s not an option with an iPad, is it? I’m starting to wonder whether it’s really designed to work with iPads at all. Help, anyone? I’m guessing that there’s a limited window for returning the item for a refund, but I’d like to be recording something, and Cubase looks the business insofar as software is concerned.