Each IP camera connected to a Synology NAS requires a license. These licenses are typically purchased from Synology or an authorized reseller. The cost can add up depending on how many cameras you plan to connect.
Synology regularly checks licenses against their authorization servers. Using a hacked key often prevents you from updating Surveillance Station Go to product viewer dialog for this item. , leaving you vulnerable to zero-day exploits. Device Blacklisting: synology ip camera license hack link