I am currently using ExcelToPdfConverter to convert an XLSX document to a PDF.
I first create the XLSX document and then convert it to PDF with the following code:
var converter = new ExcelToPdfConverter(workbook);
//Intialize the PDFDocument
var pdfDoc = new PdfDocument();
//Intialize the ExcelToPdfconverterSettings
var settings = new ExcelToPdfConverterSettings();
//Assign the PDFDocument to the TemplateDocument property of ExcelToPdfConverterSettings
settings.TemplateDocument = pdfDoc;
settings.EmbedFonts = true;
//Convert Excel Document into PDF document
pdfDoc = converter.Convert(settings);
//Save the pdf file
pdfDoc.Save(PDFFullPath);