// For complete examples and data files, please go to https://github.com/groupdocs-viewer/GroupDocs.Viewer-for-.NET
// Create new instance of GroupDocs.Viewer.Metered class
GroupDocs.Viewer.Metered metered = new GroupDocs.Viewer.Metered();
// Set public and private keys
string publicKey = "***";
string privateKey = "***";
// Set public and private keys to metered instance
metered.SetMeteredKey(publicKey, privateKey);