The “End task” option is currently available for testing in Windows 11 preview builds from the Dev Channel (Canary is not supported). You must update to build 23466 or newer, then flick two switches in the Developer section.

Open the Settings app and navigate to System > For developers.
Turn on Developer Mode and confirm the action.

Switch on the End task toggle. Now you can right-click any running app and terminate it with the corresponding option.

It is worth noting that there is a way to get the “End task” feature without enabling Developer Mode. It involves a third-party app called ViveTool, which Windows insiders often use to discover hidden features and customize various settings.

Reg

Press Win + R and type regedit.
Copy the following path and paste it into the Registry Editor’s address bar: HKCU\Software\Microsoft\Windows\CurrentVersion
Open the DeveloperSettings key under CurrentVersion. If the key is missing, right-click CurrentVersion and select New > Key. Rename the key to DeveloperSettings.
Click Edit > New > DWORD (32-bit) value and rename it to TaskbarEndTask.
Open the new value and change its value data from 0 to 1.
Restart your computer.

else cmd and type

Reg.exe add “HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\TaskbarDeveloperSettings” /v “TaskbarEndTask” /t REG_DWORD /d “1” /f

Tested to be very useful to endtask multiple app from taskbar