Hand2Note license key is issued for life when purchasing any subscription. All your subscriptions and licenses for commercial packs will be attached to this key.
You can always find your key in your profile on the official website.
The key must be entered in the software under Configuration → Other options → License:
You can use your key on any number of computers but not simultaneously. If you run Hand2Note with the same key on two PCs at the same time, the program will shut down on all devices.