Step 1: Login to your Agency Dashboard

Step 2: Login to the business you're wanting to setup for broadcasts to be sent via mobile phone

Step 3: Click on Settings

Step 4: You'll be in business information scroll down and on the left you will see to add a phone number to send broadcast from 

Step 5: Click on + New Broadcast Number button 

Step 6: Add Name and Phone number of the cell phone that will be sending broadcasts.