A legitimate activation key is a 24-digit serial number received after purchasing a license.
If you have already purchased the software but lost your key, registered users can often restore it through the ABBYY Support Center . How to Activate ABBYY FineReader 15 Abbyy Finereader 15 Activation Key
You can buy a subscription directly from the ABBYY pricing page . A legitimate activation key is a 24-digit serial