How to record both iReal and GB using earphones?

Hi all, newbie here. I want to record what I play on my piano while my kids are sleeping. so, I need to use earphones.*

fortunately, I can connect my piano*to the iPad and use GarageBand midi function (or other apps, such as Casio Cordana) to get the piano sound IN the iPad. Now I can play with iReal in the foreground, so I can follow the position indicator with my eyes and listen in the earphones to both iReal (foreground) and GB (background). this works fine.*now I'd like to record what I play, and I am pretty sure there's a way to do that. basically, I need one of these options to work (keep in mind I am connected to iPad via earphones):

a) iReal in the foreground, GB in the background, GB recording iReal audio and my piano (midi). 2 instruments in GB. issue: how do I send iReal audio to GB while keeping GB in the foreground? I don't want to export a copy of iReal audio to paste a track in GB (while I can do that, this would not allow me to follow the position indicator), I want GB (or other apps) to treat both iReal and my piano (midi) as instruments playing together.

b)*iReal in the foreground, GB in the background, iReal recording both iReal audio and my piano played by GB. this doesn't work because iReal records it's own audio and*use the iPad mic to record external audio, not the full iPad audio. I assume there should be an option for iReal to get as input the iPad output. Or better, to force iReal mic to listen to the iPad audio output.

thanks for any help or idea.