Volume control via HDMI-CEC not working

Hi all,

I’m Kodi 20.3 on Raspberry Pi OS x64(fully updated) with a Toshiba TV and a Rii mini i25 remote(which I’m pretty sure appears to the os/kodi as a keyboard). 

The rii remote pretty much just worked out of the box with kodi, but I want to be able to control the tvs volume via the rii remotes volume up/down/mute buttons. Right now when I press volume up/down/mute, the volume controls kodis built in volume, not the tvs. If I use the remote that came with tv, it can control kodi(I.e. I can navigate with the up/down/left/ right buttons) so HDMI-CEC works, but I hate the tv remote. 

From googling it seems like kodi is capable of using CEC to control the volume but I cannot figure out how. One forum post suggested that kodi has different ways of interpreting key presses and one way might not trigger kodi to pass the key press along via CEC.

I know that this tv is capable of being controlled via HDMI-CEC because I previously had a Firestick 4k that controlled the tvs volume via CEC.

Does anyone have any ideas how I can do this?