Afther you log in go to the drop down menu at the top right of the screen click on My Settings > Settings > Email & SMS Address
Click My Settings to complete your setup. Click the Settings tab and add your name, the company name, and any other relevant information.
Adding your cell phone number:
My Settings > Email & SMS Addresses > SMS Numbers > Add New SMS Number > Verify
Next, click the Email & SMS Addresses tab. Your address will already be entered. Add your cell phone number under SMS Numbers. Click Verify. A code will be sent to your cell phone number and you will add it to the popup window that will appear after clicking Verify.