Once you've entered your premium voucher code into F-Secure KEY, you can sync your password data with another device that has KEY installed.
Open F-Secure KEY (Premium).
Type in your Master Password when prompted.
Go to Menu > Connect devices. A synchronization code is automatically generated. This code is valid for only 60 seconds.
Open F-Secure KEY on the device with which you want to sync your password data.
Go to Menu > Connect devices, and type in the generated synchronization code from step 3.
Tap or click Connect.
When prompted, enter the master password that you use on your Premium device.
Once synchronization is successful, tap Confirm if syncing with a mobile device, or click OK if syncing with a desktop device.
Your password data has now been synchronized between these two devices. If you have more devices to be connected, repeat the above steps with each device. Note that you can generate the synchronization code on any of your connected devices.