How to delete a locked app, Karabiner?
It should be done in the app itself.
In “Misc” tab, press the &quot;Uninstall Karabiner-Elements&quot; button.

You can also uninstall Karabiner-Elements from command line.
$ sudo '/Library/Application Support/org.pqrs/Karabiner-Elements/uninstall_core.sh'


https://karabiner-elements.pqrs.org/docs/manual/operation/uninstall/

For any other app/file which are locked, try to unlock it by unchecking the &quot;locked&quot; box in &quot;Get Info&quot; first.
If the box is greyed out, run the following in Terminal:
cd &quot;/Applications&quot;
sudo chflags noschg &quot;Karabiner-Elements.app&quot;

Then delete it by right click &gt;  &quot;Move to Trash&quot;
Read more about noschg at man chflags.