Kde

• Right click on the dock > Layouts > Configure…
• In Settings window, go to Preferences tab
• In Actions section > Tick Press ⌘ to activate Application Launcher

Or

• Open ~/.config/kwinrc, then add:

  ...
  [ModifierOnlyShortcuts]
  Meta=org.kde.lattedock,/Latte,org.kde.LatteDock,activateLauncherMenu
  ...
  

• Reload KWin:

  $ qdbus org.kde.KWin /KWin reconfigure
  

  Github QA