Windows 10: how to get the

hello before i was used the window 10 on my pc current am update from window 10 to window 11 version 22H2 but after istall it and start to use it every time when i open my pc i got the notification which say that your window license will expire soon so you need to activate window in setting but after enter in setting they want me to enter the product key how i can get it so i need the help to get the product key plz

:)