UI scaling graphics mod

How to make it work with this mod?:

I want me some UI scaled up.

What for? VCMI has its own native UI scalling.

I don’t see it, the UI is way too tiny for my liking, it seems that HD mod has options to select how much to scale.

You’re mistaking UI scaling and resolution. It doesn’t have to be the same % of the screen as in smaller resolutions, but still.
800x600 vs 1280x960 vs 1080p (no change in world UI, city UI, only map area is larger):

example of 1280x960 (with stretched/scaled UI):

Playing 1366x768 in full-screen does what I want.