We need some more detailed description:
- Is the problem that you can not install the Fly app on the tablet?
- Or can you install it, but it will not connect to the drone?
- Did you download the Fly app from the DJI website?
- What Android version is on your tablet?
- Which APK-installer did you install, and why did you do that?
A common error when people download the app from DJI site is that they do not allow the phone/tablet to install apps from external sources (meaning everywhere else than Google Playstore). This must be enabled in the settings in the device, default is usually not allowed.