If you need further help, TechSmith support can retrieve lost licenses with proof of purchase.
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\TechSmith\Snagit\12 how to find snagit license key in the registry
HKEY_LOCAL_MACHINE\SOFTWARE\TechSmith\Snagit\2018 (Change year as needed: 2019, 2020) If you need further help, TechSmith support can