Dont work Import option from Json

I CANT INSTALL COOKIE EDITOR IN MY FIREFOX

This Add On creates an "Fakedomain.com" Cookie Entry "Cookie Quick Manager" testSameSite:someValue. You can delete it, but if you restart FF again, it appears again.

Unfortunately totally useless: cookies are shown only for the current page and cannot be edited at all. They can be exported to clipboard but must be imported as .json - what fails (error) !

Jk