You don't have to install the rpa files, you just have to move them into the Our Life folder.
1. Download the rpa file after purchase
2. From Android internal storage, navigate to Android/data/ourlife.demo.apk/files/ and create a game/ folder there if one does not already exist. 3. Move or copy/paste the rpa file to the game folder. The end path should look like Android/data/ourlife.demo.apk/files/game/[whichever_dlc_it_is].rpa (the name of the rpa file will be different depending on the DLC it is)
* Note: You may need to grant your file manager app additional permissions to access the Android/data folder.
4. Fully close the Our Life: Beginnings & Always application and re-launch it. If your device doesn't let you move files still, you can download an external file management app or connect your device to a computer to move/update the files.