SFTP Multi Factor Authentication

We are currently using "SFTP Smart Services" (https://community.appian.com/b/appmarket/posts/sftp-smart-services#) to connect SFTP and retrieve and send files to folder of SFTP. We connect using External System Key that uses username and password. Recently, the requirement has changed to have a multi factor authentication for this connect, i.e., every time we connect to SFTP there will be an OTP sent to an email ID and that needs to be used to connect to SFTP along with user credentials. Please let me know any leads on this.