If you want legal alternatives or legitimate ways to run Windows on a Mac, I can help with:
This is the most common method associated with "no activation code." Crack groups attempt to modify the application's executable code to skip the license verification step.
Searching for "Parallels Desktop Mac for free no activation code license key exclusive" is understandable – software costs add up. But the risks of downloading cracked or "pre-activated" versions far outweigh the benefits. You could lose your personal data, compromise your Apple ID, or turn your Mac into a zombie in a botnet.
Some searches promise "exclusive" license keys. These are typically volume license keys (VLKs) meant for enterprise deployment that have been leaked.