You will need this key during the installation process. Once the installer runs, it will prompt you to enter the key to verify your license. Without it, the software will typically not install, or it will install as a restricted trial version.
Because Photoplus X8 is no longer sold, the market is flooded with illegitimate offers. Users should be cautious of: Serif Photoplus X8 Product Key
Serif offers Affinity Photo, the direct successor to PhotoPlus. You will need this key during the installation process