How do I cancel a print job
This question is not related to LibreOffice but to the printing/spooling system of your operating system (LibreOffice passes - like any other application - data to be printed to the printing subsystem of the operating system and after that has happened, LibreOffice loses any control about the print process and you can’t cancel a print job from within LibreOffice). Therefore nobody could provide a sound answer, if you don’t provide information about your operating system.
For Windows 10: Take a tour here or any of the other plenty search results of an internet search for “Windows cancel a print job”.