So basically you need:
A) a USB keyboard
B) working power socket to charge the tablet
The easiest solution that comes to my mind is to just use a bluetooth keyboard and plug the USB-C directly to the iPlay.
I’ve got a bluetooth keyboard and it’s pretty reliable with all of my devices. You can use a bt mouse together with it and get a totally wireless setup, which is nice and clean.
If you absolutely need a USB keyboard then sorry, but anything that resembles a Hub seems not to work on this device.
Anyways, I did a test for you. I have a USB otg thingy with a USB-A port and a micro-USB power pass-through lying around.
I just tested it with 1) one USB-C to micro-USB adaptor as a middle man, 2) a micro-USB Power cable from the otg adapter to the wall socket and 3) a USB keyboard in the USB-A adaptor socket to see if this setup might work, but it didn’t. There was no answer at all. In fact, it just killed my USB port entirely until I rebooted the tablet.
Maybe it’s just this adapter, maybe some other USB pass-through adapter would work, but I wouldn’t bet on it.
If your only need is a keyboard, I’d say go for a bluetooth keyboard. You’ve got a nice solution right in front of you. Batteries last a long time and you can even use rechargeables if you do many hours of typing a day, i.e. coding.
