If you have an older version and are looking for a 7.10 code, check your original purchase email. Most licenses allow for minor version updates, and the support team can often help you retrieve a lost key if you provide your proof of purchase.
Finding a through "exclusive" or unofficial channels is often a search for a shortcut to a professional-grade cabinet design tool. However, the way Polyboard handles licensing is unique and doesn't rely on generic serial keys found on the open web.