This is just one way to do this. There are others. Like all things linux people have their own preferences on how to do things. I have done it this way as well as others for years now and have never broken a system. This is just how I do it.
@Clu had asked me how I installed this Share Your Desktop - #4694 by BONK theme. Instead of a pm I figured I would just write it up here in case anyone else finds it interesting.
We start with Endeavour OS basic Plasma install:
Open System Settings and go to Appearance:
Go to Global Theme and select Get New Global Themes:
Scroll through to find it or search for Win11OS Global Theme hover over it and then select install. Follow the prompts. system settings can be buggy sometimes and error out. Usually a quick reboot and return clears it up. Like I said there are ways to just download the theme and apply it your self from KDE store:
Don’t click use it can be buggy instead apply with System Settings
Application Style leave breeze.
Plasma Style should be applied already:
Color Scheme should be applied already:
Window Decorations should be applied already:
Icons should also be installed already I chose win11 black:
Cursors-not all themes have their own cursor file but this one does so might as well use it win11 black here as well:
Splash Screen-not all themes have this either this does and should be already applied:
If there is a sddm theme or a log in screen added you wont see this part it happens in the back ground when you install the global theme. It will ask for your password as it requires sudo. Don’t panic you’re fine 
Still with me? 
Ok so this is it and the theme is applied. At this point I would reboot. In general linux users do not like to reboot. I personally never understood it but to each their own.
Enjoy the newly installed theme 
"But wait this doesn’t look like the theme in your screenshot! 
This is where we talk about KDE Store. Some times there are parts of a theme that you can see when browsing system settings that aren’t available there. One thing is Kvantum and Kvantum themes. If you find a theme you like in system settings look it up on https://store.kde.org/browse/ This is where you can read about all of the features of the theme that may be availiable via download and not via system settings.
Download the Kvantum theme:
Now we need to add a folder. You can do this in dolphin. Click on home in dolphin and hit CTRL+H
The directory/folder we are looking for is hidden. Again don’t panic you’re fine 
Create the directory/folder here called Kvantum Themes.
Now go to your downloads folder and you will see a compressed Kvantum file. We need to extract that to the folder we just created. Right click and select extract to you need to. Hit CTRL+H again. :
Now we need to install the kvantum-qt5 package. Open a terminal and type yay kvantum:
The output should look like this:
Summary
[elloquin@elloquin-eos ~]$ yay kvantum
30 aur/kvantum-theme-sweet 20200613-1 (+0 0.00) (Orphaned)
Dark and modern Kvantum theme based on the Monochrome KDE theme
29 aur/retrosmart-kvantum-theme 1.0b-1 (+0 0.00)
Retrosmart theme for Kvantum
28 aur/whitesur-kvantum-theme-git r33.a7f777c-1 (+0 0.00)
WhiteSur theme for Kvantum
27 aur/kvantum-theme-otto-git 0-1 (+0 0.00)
Otto theme for kvantum
26 aur/kvantum-theme-moe-git r20.4c1f4df-3 (+0 0.00)
Moe is a light theme, with blur transparencies and red tones with gradients.
25 aur/kvantum-theme-matcha-git r9.283b5b1-1 (+0 0.00)
Matcha theme for Kvantum
24 aur/kvantum-theme-akava-git r14.0c22434-1 (+0 0.00)
User oriented Kvantum theme for KDE
23 aur/kvantum-manjaro-theme-git r37.a316110-1 (+0 0.00)
Kvantum Manjaro theme based on works of Papirus Development Team and Tsu Jan
22 aur/kvantum-theme-materia-blur 20200312-1 (+0 0.00)
Materia Blur (discontinued) theme for KDE Plasma 5
21 aur/kvantum-theme-fluent-git r17.890a450-1 (+0 0.00) (Orphaned)
fluent a windows 10 like theme for Kvantum
20 aur/kvantum-theme-breeze-git r5.30ff5a7-1 (+0 0.00) (Orphaned)
Breeze theme for Kvantum
19 aur/sensual-kvantum-theme-git r555.52b16a2-1 (+0 0.00) (Orphaned)
Sensual Breeze theme for Kvantum
18 aur/kvantum-theme-qogir-git r48.17ff307-1 (+1 0.00)
Qogir theme for Kvantum
17 aur/kvantum-theme-sweet-mars-git r121.134ff45-1 (+1 0.01)
Sweet Mars theme for Kvantum
16 aur/kvantum-theme-sweet-nova-git r157.93b2375-1 (+1 0.01)
Sweet Nova theme for Kvantum
15 aur/kvantum-qt4-git 0.10.5.r16.g45792f7-1 (+2 0.00)
SVG-based Qt4 theme engine plus a config tool and extra themes
14 aur/kvantum-theme-vimix-git r35.8ecc8db-1 (+2 0.00)
Vimix theme for Kvantum
13 aur/kvantum-theme-orchis-git r5.018fd0f-1 (+2 0.03)
Orchis theme for Kvantum
12 aur/kvantum-theme-mcmanjaro-git r38.506ac29-1 (+2 0.00)
McManjaro theme for KDE Plasma 5
11 aur/kvantum-theme-adapta 20180828-1 (+2 0.03)
Adapta theme for KDE Plasma 5
10 aur/kvantum-theme-chromeos-git r18.3fcbdb4-1 (+3 0.00)
ChromeOS theme for KDE Plasma 5
9 aur/kvantum-theme-nordic-git 1.9.0.r33.gce75292-1 (+3 0.22)
Nordic theme for KDE Plasma 5
8 aur/kvantum-theme-sweet-git r157.93b2375-1 (+6 0.29)
Sweet theme for KDE Plasma 5
7 aur/ant-dracula-kvantum-theme-git v1.3.0.r57.g1eb71ee-1 (+6 0.97)
Ant Dracula theme for Kvantum Qt style
6 aur/kvantum-qt5-git 0.17.0.r0.g231924bd-1 (+6 0.00)
SVG-based Qt5 theme engine plus a config tool and extra themes
5 aur/kvantum-theme-layan-git r28.f7f205f-1 (+8 0.51)
Layan theme for KDE Plasma 5
4 aur/kvantum-theme-arc 20180614-3 (+12 0.87)
Arc theme for Kvantum
3 aur/adapta-kde-git r180.ae539ff-1 (+20 0.00)
Complete Adapta theme pack for KDE Plasma using Kvantum theme engine (git version)
2 community/kvantum-theme-materia 20210722-1 (38.5 KiB 565.0 KiB)
Materia theme for KDE Plasma 5
1 community/kvantum-qt5 0.20.1-1 (1018.1 KiB 7.6 MiB)
SVG-based theme engine for Qt5 (including config tool and extra themes)
==> Packages to install (eg: 1 2 3, 1-3 or ^4)
==> 1
[sudo] password for elloquin:
resolving dependencies...
looking for conflicting packages...
Packages (1) kvantum-qt5-0.20.1-1
Total Download Size: 0.99 MiB
Total Installed Size: 7.56 MiB
:: Proceed with installation? [Y/n] y
:: Retrieving packages...
kvantum-qt5-0.20.1-1-x86_64 1018.1 KiB 2.35 MiB/s 00:00 [--------------------------------------------------------------------------------------] 100%
(1/1) checking keys in keyring [--------------------------------------------------------------------------------------] 100%
(1/1) checking package integrity [--------------------------------------------------------------------------------------] 100%
(1/1) loading package files [--------------------------------------------------------------------------------------] 100%
(1/1) checking for file conflicts [--------------------------------------------------------------------------------------] 100%
:: Processing package changes...
(1/1) installing kvantum-qt5 [--------------------------------------------------------------------------------------] 100%
:: Running post-transaction hooks...
(1/3) Arming ConditionNeedsUpdate...
(2/3) Updating icon theme caches...
(3/3) Updating the desktop file MIME type cache...
[elloquin@elloquin-eos ~]$
Open Kvantum Manager
Click select a kvantum theme folder. This is the one we created in ~/.local/share/Kvantum Themes
Go to change/delete current theme and select this one at the bottom:
Things should start looking like this at this point:
Now go to system settings and go to application style and change it to Kvantum dark.
Reboot
Personally I make a few more adjustments. You will notice the default blur settings have a grainy effect to them. Go to System Settings and then to Workspace Behavior then Desktop Effects and hit the cog for blur settings and change to this:
Almost done still there? Bueller…Bueller…
This theme has a menu widget recommended. We need to install it. Hopefully your not 
at this point.
Right click the menu button and select add widgets you want to install Menu 11 :
Right click the menu icon again and select show alternatives. Select Menu 11.
Hit switch to set it. When you are all done it should look like this:
like example
