I was trying to flash the update for android oreo 8.0 UL-Z018-WW-80.20.96.109-user-zip with twrp recovery but
it didn't work so I've extract the system-img and boot-img from the zip file and flashing with twrp worked just fine,
if it helps here are the files.
https://drive.google.com/file/d/1PV_0UB4MGFvu8a1tM6BKpOQErQeLlmxg/view?usp=sharing
just put it on your sd-card and flash boot-img then system-img ,this will remove twrp and install factory recovery as well .
it didn't work so I've extract the system-img and boot-img from the zip file and flashing with twrp worked just fine,
if it helps here are the files.
https://drive.google.com/file/d/1PV_0UB4MGFvu8a1tM6BKpOQErQeLlmxg/view?usp=sharing
just put it on your sd-card and flash boot-img then system-img ,this will remove twrp and install factory recovery as well .