if your device is encrypted (you have NOT flashed DFE), then OTA should be ok.
if your device is NOT encrypted (you have flashed DFE before), then you have to flash
the ROM manually in TWRP:
1. Download update
2. Reboot to twrp/ofox
3. Flash rom and custom kernel if you use one
4. Flash #dfe if you are decrypted
5. Reboot to system and profit.