Add Signature In PDF

Hi Experts, Consider a scenario, Person A uploads one file and sent it to person B. Person B can able to view it and add comment (i.e able to add their sign) and that can be send to Person A .Now Person A able  to view the commented document. How can I achieve this ? Thanks In Advance.
1 answers

Use an external service for this like the ones used in these two modules from the app store:

Or use the signature widget, use the image from there to create a second pdf and merge the pdfs with functions from the community commons module from the app store: