How to License On-Screen Takeoff (OST)
Select ‘File>Check Authorization’ to enter the license key: OST@01AR8Z3BL5FH
Select ‘Validate’ and then ‘Activate’.
When it is Activated the letters ‘OST’ will show at the bottom right and there will be an option to return the license (see image). Licenses are returned automatically when OST is closed.