I have not tried this myself and do it at your own risk! SideQuest is used by many people to sideload Android apps to their Oculus. Chances are this would also work for sideloading to a phone. You will need to have Developer mode enabled and allow unknown sources.
I am pretty sure the DeoVR version in the SideQuest library will not work unless you use GearVR. So you likely will still have to find the .apk somewhere else.
You can google your phone + Android version on how to enable Developer mode. In most cases it's the same default way, but not always.