Setting up OpenWRT in ZVM, any guides available?

On one of the official ZimaOS videos it shows OpenWRT running as a VM in ZVM.

My main router (2.5GbE Flint 2) is currently being swapped out under warranty (PSU or mainboard issue) and I am running a backup 1GigE router, so would like to try ZimaOS ZVM OpenWRT to get back to 2.5GbE speeds..

System spec is Dell 3050 micro 7500T 16GB RAM, 500GB NVME with Intel 1GbE, Realtek 2.5GbE internal (via Wifi M2 slot) and 1 x external Realtek USB 2.5GbE NiCs.

I have tried installing in ZVM using then OpenWRT x86 generic .img, which runs the install but then does not boot in the VM afterwards, so I have missed a step.

Any guides to setting up OpenWRT in a ZVM?