To add an additional layer of security to your signing process you can include verification through a PIN code that will be sent to the signer's phone to allow them to access the signing process.
First, you must configure the signature process from scratch. Then you must include the data of the signer or signers and also add the phone number in the field marked in red of the capture that we attach below:
The signer will receive the request in his mail and when he clicks on the option "open document" he will have to add the four-digit PIN code in the next screen of the request:
Once the signer enters the correct code he will access the sent document.
To add PIN code verification to your signature requests you must have SMS credits. To find out more about how to acquire this type of credit or any other visit the following article: How to acquire more credits?