Where you find your serial number depends on your purchase method:
However, I can help you with legitimate options: u-he diva serial number mac
If the plugin is in "demo mode" (indicated by occasional crackling or a "DEMO" watermark), a registration window usually appears upon opening. If not, click on the u-he logo in the top center of the Diva interface and select "Enter Serial Number." Enter Your Credentials: Where you find your serial number depends on
To authorize on macOS, you must enter your unique serial number and user name into the plugin's interface after installation. Serial numbers for u-he products are person-based rather than machine-based, meaning a single license covers all your personally owned computers, regardless of whether they run macOS, Windows, or Linux. 1. How to Locate Your Serial Number License Transfers - Page 6 - u-he Forum - KVR Audio
If you purchased Diva second-hand, the seller must initiate a transfer through the u-he Support page . Transfers are free if the license has been owned for at least nine months; otherwise, a small fee applies . License Transfers - Page 6 - u-he Forum - KVR Audio