To install via commandline:
sudo installer -pkg "path/to/AutoCorrect.pkg" -target /
To set the license key, for each user:
defaults write com.texthelp.AutoCorrect Serial -string "[product-code]"
e.g. defaults write com.texthelp.AutoCorrect Serial -string "12345-12345-12345-12345-12345"
MDM .mobileconfig profile - Allows AutoCorrect access to the keyboard to allow corrections. Example here.