array(
            'user_registration'      => __( 'Student creates a new account', 'lifterlms' ),
            'access_plan_purchased'  => __( 'Student Purchases an Access Plan', 'lifterlms' ),
            'course_enrollment'      => __( 'Student enrolls in a course', 'lifterlms' ),
            'course_purchased'       => __( 'Student purchases a course', 'lifterlms' ),