Hey Dodulan,
Thanks for your post.
While I do want to see how I can help here. Please note, this is not a support forum. This is for user to user contact. Contact support below with any issues for the quickest resolution.
https://www.ikmultimedia.com/contact-support/As long as this keyboard has a 5-pin MIDI connection, this will certainly be possible. From what I see online, this should be the case.The iRig Pro Will include a 2.5mm to 5-pin DIN cable for MIDI connections.
If this keyboard has 'local' or internal sounds. Turn these off in the keyboard's settings, or turn the Volume down on this unit. What we are looking to do here is send MIDI not audio to the iOS device connected. This means the sounds sound be coming from your iRig Pro I/O. Connect headphones or speakers to the iRig Pro I/O to hear GarageBand's playback.