Creating signer session with SMS authentication

Hi,

We have received some complaints from customers that are not receiving the OTP in their signature process.

We already raised a ticket to OneSpan support with the incident, and they told us that apparently the sms is being triggered without any issue from their systems. 

We are using OneSpan REST API to create and process all the transaction mostly based on the OOTB rulesets you provide.

Hi, We would like to integrate esign solution to our application, while creating the signer CreateSignerSessionToken, we want SMS authentication to be enabled in that session. Could you please advise how this can be achieved.