Hi,

In Aximmetry's menus, you set up multi-machine for LED walls just as you would do for other camera compounds. So you can follow the start of this documentation: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/multi-machine-environment/multi-machine-setup/#setting-up-the-controller-machine
After that, you should follow what is written here in the LED wall documentation: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/led-wall-production/using-led-walls-for-virtual-production/#multi-machine-configuration
And here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/led-wall-production/using-led-walls-for-virtual-production/#multi-machine-settings

Note, there is a big difference between LED wall's multi-machine and the rest of the studio camera compounds' multi-machine.
In the studio camera compounds, the multi-machine can separate the camera's Input-Output per machine:

While in LED walls, the multi-machine can separate the rendering of the LED walls and their Output:

And you can not separate the camera's Input-Output per machine in LED wall like in other studio camera compounds.
It is very unlikely you would want to do that anyway, as using the same LED wall with more than 1 camera at the same time with continuous outputs makes little sense. Such a setup can cause all kinds of issues, like the cameras can not look at the same point on the LED wall as they would see the frustum of the other camera.

While using multi machine with LED walls will spread the load of rendering the LED walls on multiple machines, there are other reasons to do so.
If you render all your LED walls on remote machine(s), you can achieve things discussed here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/led-wall-production/using-led-walls-for-virtual-production/#switching-between-cameras

Warmest regards,