Need your help: I have a web application (back - .NetCore; front - Angular).
How to sign an Excel file generated on the server using an EDS on a client? It's required that, as a result, the user can receive the signed document and the digital signature is visible inside when he open the .xls file. In addition, using a separate button, I need to be able to save the document in PDF with a visible signature that contained the full name, date and time Documents NOT signed with EDS in .xls and .pdf formats are created on the server. But how to embed a digital signature in them on the client?