Linux installations using the Altova installer for Linux typically store the license in a simulated Windows path:
: A local binary license file created after entering a key code directly into the software. Altova Xmlspy License File Location
If the software was deployed for everyone on the machine, it sits in the common data folders: C:\ProgramData\Altova\XMLSpy\Keycode.xml ProgramData Linux installations using the Altova installer for Linux
If you can still open the program, you don't need to hunt through folders. About XMLSpy Altova Xmlspy License File Location