Digital Signature Certificate in the PF , Gratuity and Employer certificate

Hi Team,

We are implementing onboarding journey and for few documents like PF , Gratuity & nomination form they want to add 'digital signature certificate' in the form which will be uploaded by an employee. Would be really great if any one could suggest how to achieve this requirement.

Please see the business process below for further details.

Pending worker will download the PF , Gratuity & Nomination form from the document task > They will manually sign the document and upload in the next step > Once it has been uploaded , document needs to be 'digitally signed' so that employer just need to verify the content.