How to FLASH CUSTOM ROM on AB Partition

Unable to mount data or system error to flash additional zips please reboot recovery to switch to the update slot zip to inactive slot: B Devices on super may not mount until rebooting recovery To flash additional zip please reboot recovery to switch to the update slot top android slot games zip to inactive slot: B Devices on super may not mount until rebooting recovery To flash additional zip please reboot recovery to switch to the update slot

top 5 slot zip' Flashing AB zip to inactive slot: A Updater process ended with ERROR: 1 To flash additional zips, please reboot recovery to swith updater