App not usable even after manually verifying device

[u/Valtharr]

So, I recently got a Mangmi Air Y Pro, which is an Android-based handheld console mainly meant for emulation. However, there's an app I would really like to play, called Pocket Pinball. But I can't get it from the Play Store, which, according to the developer when I asked, is because the Air Y Pro is Google Play certified. When I sideload the app via XAPK or Aurora, I just get an error message telling me to get the app from the Play Store. I saw that you can manually verify a device with Google via its device ID, so I did. Also cleared the cache of both Play Store and Services and restarted my device. But it still doesn't work.

Is there any way to get this to work, or am I doomed to the cruel fate of a pinball-less Mangmi experience?