Your company will need to have SMS Notifications enabled in their account in order to enable this functionality.
To receive SMS notifications, you must have accepted your manager/employer's RotaCloud invitation and created a login.
First, add your mobile number into your profile (it may have already been added by your manager/employer).
Once you've entered your mobile number, you'll receive a text message asking your to verify your phone number.
Just reply with the word 'Yes' (without quotes) to verify the mobile number and complete the SMS setup process.