In C#, add a reference to libzkfpcsharp.dll in your Visual Studio project.
Ensure the latest ZKFinger SDK 5.x/ZKOnline SDK is properly installed. Alternatives for Developers
If you receive errors stating that libzkfpdll.dll is missing, try the following solutions:
Develop custom biometric attendance, access control, or secure login software. Supported Devices
The most common modern USB optical scanners. ZK4500: A popular, reliable previous-generation sensor. SLK20M / ZK8500R: Other ZK-series biometric devices. Installing and Using the Full ZKFinger SDK