// Path to the output merged PDF file.
var outputPath = "TestMerge.pdf";

// Create a new instance of Merger.
var merger = new Merger();

// Create MergeOptions.
var opt = new MergeOptions();
opt.AddInput(new FileDataSource(inputPath1));
opt.AddInput(new FileDataSource(inputPath2));
opt.AddOutput(new FileDataSource(outputPath));

// Process the PDF merging.
merger.Process(opt);