Default [Q] No backup option in recovery menu. (Custom recovery menu not installed?)

I've successfully rooted an LG G2 (D802) running 4.4.2, using IORoot v25.

It appears that I have the following apps working: SuperSU, ROM Manager, TWRP Manager. X-plore (all seem to be able to obtain root permissions).

I want to install a custom ROM so I need to back up the stock ROM (etc) but I am having no luck.

For example, Using ROM Manager, I have tried backup up the ROM in 4 ways:

1. Recovery Setup > [Install or Update] ClockwordModrecovery. Then hit "Reboot into Recovery". It reboots into recovery menu, but no back up options listed.

2. (With CWM Recovery still set), hit "Backup Current ROM" (says the backup directory will be /mnt/shell/emulated/clockworkmod/backup). Still it boots into the recovery menu without any backup options, and when I reboot, nothing appears in the /mnt/shell directory.

3. Use ROM Manager to select TWRP recovery. Hit option to go to recovery mode. Still no backup options are listed, so I reboot.

4. (With TWRP Recovery still set), I hit "Backup Current ROM" (underneath it says the backup directory will be /sdcard/TWRP/BACKUPS/0225b99d9a5159f0) STILL, no backup options, and no directory /sdcard/TWRP.

Any advice?

Thanks