How can I create a signature appearance with text and an image?

It is ideal to not only digitally sign a document using digital certificates but also leave a visual mark on the document indicating that it has been signed. For this, UniPDF allows you to create appearance fields with text and/or images to indicate the status of the document. 

You can check out an example of using UniPDF for creating signature appearance fields here. 

- https://github.com/unidoc/unipdf-examples/blob/master/signatures/pdf_sign_appearance.go