TextSignatureWithZOrder.cs

// instantiate the signature object
using (Signature signature = new Signature("Sample.pdf"))
{
    // setup options with text of signature
    TextSignOptions signOptions = new TextSignOptions("John Smith");
    // set Z-Order
    signOptions.ZOrder = 10;
    // text rectangle size
    signOptions.Height = 100;
    signOptions.Width = 100;
    // if you need to sign all the pages of document
    signOptions.AllPages = true;
     
    // sign the document 
    signature.Sign("signedSample.pdf", signOptions); 
}