As of MDL-78511, moodle core includes the AWS SDK to support the use of SNS for multi-factor authentication: https://github.com/moodle/moodle/commit/9b98f78d2a4bc2ef13143a17530e73ba22c1dae6 This may mean that this plugin is no longer required from 4.4 onwards. We should do some testing to confirm this.