Instead of searching for keys, you might consider these that do not require a license key:
Instead of looking for a license key, look for ways to secure your free VNC server. Many GitHub repositories offer tools to run VNC over SSH tunnels. Search Query: vnc over ssh wrapper github Containerized VNC (Docker) vnc server license key github
TigerVNC is a high-performance, platform-independent implementation of VNC. It focuses on speed and performance for 3D and video applications. Instead of searching for keys, you might consider