Are seriously asking with a straight face? Just do what a generation of people have done with Windows and run an unlicensed version of macOS. There's a whole generation of people who can recite Windows product keys off by heart. (FCKGW, anyone?) Entire empires of indie web development will have been done on improperly licensed versions of Windows.

As for people working in a serious professional corporation that cannot condone casual piracy, buy a Mac mini and expense it, or get an account on MacStadium.

There are the illegal ones, and the legal ones on cloud providers.