UR242 MIDI Keyboard Recommendation

I’m seeking any recommendations for a cheap MIDI keyboard/controller that will work with the 5-pin midi input on the UR242. I’m using it on an iPad with a guitar and mic plugged in but would also like to put in a keyboard via the MIDI in on the back of the unit to drop in some basic strings/drums etc. I have an iRigKeys that only has USB-MIDI out that I can’t connect so was hoping to find an alternative. The key here is cheap, it’s easy to find a USB-MIDI keyboard for less than $100 but one with 5-Pin seems really difficult to source.

Please note I’m a pretty much a complete noob when it comes to keyboards and MIDI, I’ve used the iRigKeys which works a treat direct to the iPad and my Mac, it just isn’t compatible with the 5 pin inputs on the UR242. All suggestions are greatly appreciated. Thank you.