EXFO FTB-2 - Manual (Page 65)

Getting Started with Your Unit
FTB-2 and FTB-2 Pro 55
Activating Software Options
5. In the Platform Options tab, use the Browse button to locate the key
file that you want to use.
6. Tap Activate.
The option indicator will turn into a green check mark to confirm that
the option is now active.
7. Tap Close to exit the Option Activation window.
Note: At this point, if you have used a USB key to copy your key file, you can
remove it as it is not required to use your new options.