Dark theme or dark mode for Lubuntu 20.10

[Wugubee]

With Lubuntu 20.10 what is the best way to enable dark mode or theme,
I want all of them to be dark, file manager, lubuntu menus, and so on,

I did follow this link: Lubuntu 20.04 fully dark theme (background windows too)?

but it makes the menu start icon goes blank, why not make it into built in official?

[Wugubee]

I see obconf is installed by default at lubuntu 20.10, but I can not get it working,
may be I need qt5ct installed?

[Wugubee]

I solved it by my self, by using kvantum manager,

https://www.youtube.com/watch?v=oxG54VF8XPo

####kvantum (unified theme manager)
apt install adapta-kde

For additional themes

apt install qt5-style-kvantum-themes