How To Root Fly FS455 Nimbus 11
1.Download And install MTK Android USB Drivers.
2. Download TWRP_root_files_FS455.7z and extract it.
3. Copy the supersu.zip file into the phone and turn off the phone.
4. Start SPFlashTool, click scatter-loading and select the file MT6737M_Android_scatter.txt from the TWRP-3-1-0-0 folder.
5. Press Download and immediately connect the switched off phone to the PC, after which the TWRP recovery will be performed, at the end a window with a green bird will pop out.
6. Disconnect the phone from the PC. press and hold the volume UP + POWER buttons in the menu to select “recovery”, and then TWRP will boot.
10. Select the item Install -> select the UPDATE-SuperSU-v2.82.zip archive and install it by making the swipe to the right (swipe to install).
11. After installing the archive, go back to the main TWRP menu and select Reboot -> system. After the done actions, the smartphone will reboot into the Android system already with root rights.