using GroupDocs.Signature; using GroupDocs.Signature.Options; namespace SignXLSXwithImageSignatureUsingCSharp { internal class Program { static void Main(string[] args) { // Set License to avoid the limitations of Signature library License lic = new License(); lic.SetLicense(@"GroupDocs.Signature.lic"); // load the source XLSX file Signature signature = new Signature("input.xlsx"); // Initialize image sign options with signature image's path ImageSignOptions options = new ImageSignOptions("signature.jpg") { // set signature position Left = 100, Top = 100, AllPages = true }; // Save output XLSX to disk signature.Sign("output.xlsx", options); } } }