In order to make the SMS service more sustainable, we made some changes to it in May 2019.
Change in SMS access
Triggers and actions from the SMS service will no longer appear when creating Applets with the Applet composer.
Applets created on the Developer Dashboard are still able to use triggers and actions from the SMS service.
Transitioning to Notifications from the IFTTT app
Existing user-created SMS Applets will be transitioned to use Notifications, powered by the IFTTT app ( Android / iOS ).
SMS Alternatives
The SMS service isn’t the only way to send yourself notifications with IFTTT. A list of alternatives can be found here.