Hi Jhon Edwin,
Thank you for using Syncfusion products.
The Excel workbook to PDF conversion is added in our Essential Studio version 8.2.0.18. The ExcelToPDFConverter class library not included in the version 6.4.0.15. So, we recommed you to upgrade to our latest version for this support.
Please get the latest version from the follwoing link.
Please go through the following online sample for more details on ExcelToPDF conversion.
Please let me know if you have any further clarifications.
Thanks,
Sridhar.S