Sideloading means installing an Android app
without the use of the Play Store.
To sideload an app you first need to download the “Android Package File” (.APK). You can download it directly to your Android device, but some may find it necessary to download the file to a desktop computer, and then transfer it to the phone by using a USB cable, Bluetooth, or a cloud storage provider like Dropbox or Google Drive.
Locate the file on your phone. Use the Downloads app to find it. Tap on the file name; if a warning pops up asking for your permission to install it, give it permission to do so. If asked, click “Install”.
The app should now install unless there is a compatibility issue with your specific Android device.