While they no longer provide technical updates, you can occasionally find "Legacy Activation" portals on the Corel website where you can enter your Passport ID to generate your own keys.
Finding a "top" or "working" activation key for Pinnacle Studio 14’s MPEG-4 codec online is a common hurdle for users of this legacy software. Because Pinnacle Studio 14 (released in 2009) is now considered "End of Life" by Corel (the current owner), the original automated activation servers for specialized codecs like MPEG-4 and Dolby Digital are often offline or unsupported.
Searching for a "Pinnacle Studio 14 MPEG4 activation key" is often a dead end in 2024. Between server shutdowns and security risks, the best path forward is usually migrating your projects to a modern editor that handles MPEG-4 natively.