I have two different KEYs. Is it all right to use one KEY for both windows pc and linux?
Linux OS is not part of the consumer supported OS but KEY is supported on iOS, Android, Windows and Mac.
However, F-Secure KEY is slated to end in August ending so we suggest you upgrade to F-Secure ID Protection.
See steps in the link below
I have F-Secure KEY subscription. How can I switch to F-Secure ID PROTECTION? - F-Secure Community