Hi,

We have documentation about LUT MEASURE here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/led-wall-production/using-led-walls-for-virtual-production/#lut 

You should first turn it on:

Then set it up like in the documentation, that all the rectangles are inside all the virtual rectangles.
Then press play and wait until it completes:

Warmest regards,