I am not able to add a signature to an e-consent form after the participant has signed and submitted the e-consent survey.
In order to add your signature to the e-consent form after the participant has signed and submitted the survey, you need Edit survey responses user rights for the e-consent. To check or give yourself these rights:
Click User Rights from the left hand column
Hover over your username then click Edit user privileges
Ensure you have Edit survey privileges for your e-consent survey
Once you have these rights, return to the record of interest and open the survey completed by the participant