Amazon Pinpoint now includes a one-time password (OTP) management feature

Amazon Pinpoint now includes a one-time password (OTP) management feature. An OTP is an automatically generated string of characters that authenticates a user for a single login attempt or transaction. The OTP feature makes it easier to add OTP workflows to your application, site, or service. You can use this feature to generate new OTP codes and send them to your recipients as SMS text messages. Your applications can then call the Amazon Pinpoint API to validate that the OTP code the recipient entered is valid. 

Source:: Amazon AWS