Android App Side Load Ebooks into Kobo Android App

Earlier this year, I switched from Barnes & Noble to Kobo because B&N has discontinued their app for computers. I do have their app on my computer, but I had to jump through a few hoops to get it installed when we upgraded our hardware.

I do not own a dedicated Kobo ereader. Rather, I have a Lenovo tablet onto which I've loaded the Barnes & Noble Nook app as well as the Kobo app. I would like to side load books into the Kobo app, but all the articles I've seen are for the actual Kobo ereaders rather than just the Android app.

Is there a way to do this?

Thanks.