Press and hold the Option (Alt) key, then right-click the app icon in the Dock
Click “Force Quit”
If the app won’t respond, press Command (⌘) + Option (⌥) + Esc
Select the app from the Force Quit Applications window
Click “Force Quit”
If needed, select the app and click “Relaunch” (if shown)
Open Activity Monitor (Applications > Utilities > Activity Monitor)
Search for the app, select it
Click the Stop (X) button
Choose “Force Quit”
If the app still won’t quit, log out or restart your Mac