I should phrase it politely, maybe start with a thank you and then explain the situation. Make sure it's clear that the keygen isn't something I can provide. Emphasize the benefits of using legal software, like support and updates. Make the user feel guided towards the right path without making them feel attacked.

Possible structure: Greeting, explanation of the issue, warning about illegal methods, offer of legal solutions, contact information, and a positive closing.

Stay compliant, safe, and empowered! 🚀

Also, maybe the user is a developer who needs to generate keys for a different reason. But that's less likely. Most users aren't looking to distribute or pirate software. So the main points are: warn against illegal keygens, suggest legitimate options, and provide guidance on where to find help.