Modifier not working on opencart?

Question

opencart

Good afternoon!
I have such a problem, usually I added modifiers to opencart sites through the admin panel, the other day I saw that modifiers can be added directly to the system folder and they work.
I deployed opencart version 2.3, created a simple modifier that would change the color of the body to check how it works, and ultimately nothing happens. Opencart simply does not see this modifier, I checked in system / storage / modification there are also no changes, I also correctly registered the paths in the modifier.
Then I thought, maybe I screwed up with the modifier, found a ready-made modifier on the Internet, uploaded it, nothing too. After uploading the modifier, I updated the modifiers in the admin panel.
Can someone tell me what I'm doing wrong...