1. Enable installing "unknown apps" option on your phone
Android 7 (Nougat)
- Go into Settings.
- Tap Security (or Lock Screen and Security).
- Scroll down to the Device Administration section, and enable Unknown Sources.
Android 8 (Oreo) and Android 9 (Pie)
- Go to Settings.
- Tap Apps and Notifications.
- Tap on the 3-dots icon located at the top right of the screen.
- Select Special access.
- Tap on install unknown apps.
- Enable the permission for UNiRIDE app to install.
2. Locate the apk using your phone's "File Manager".
3. Enable permission and install the app.