Add a digital signature to PDF file from Delphi

Question

I have purchased a digital signature and have the dongle for it. I have a Delphi project from which I generate invoice PDF and I need to add that digital signature to the pdf files created. Is there any way I can do this programmatically using Delphi? I am looking for a free Delphi component to use. I am currently using RAD Studio 10.4. I am making the PDF using Microsoft print to PDF and sometimes dopdf.

I have checked the below but it is a paid product.

https://www.gnostice.com/nl_article.asp?id=268&t=Generating_Digitally_Signed_PDF_Documents_In_Delphi

I have checked this Acrobat component, but I am not able to figure out if we can sign the pdf using this, like we sign manually: https://www.thoughtco.com/adobe-acrobat-pdf-files-delphi-applications-1056893

Terceira

Would you be OK with Delphi calling non-Delphi code via the command line to sign the file? – Snowberry

@alcalde, yes it works for me, please share the solution! – Terceira