How to enable dark mode in Dolibarr

I have a working Dolibarr 13.0.2 or higher installation. According to our requirements we need to customize the default eldy theme. In default eldy theme I saw a Dolibarr configuration constant, THEME_DARKMODEENABLED. I believe if we can set the value for this constact THEME_DARKMODEENABLED=1, the dark mode will start working. But I can’t see any option to enable it from Dolibarr display settings page. But I can enable from other setup. I think it is better if we have an option to enable it from the display


setting page itself.

THEME_DARKMODEENABLED=2

in Setup → other
For theme ELDY