First, open the TextUs Web Extension and select the Phone #s on Page icon (if not opened by default).
Edit and add new contacts into your TextUs account.
Select Import to Group. You're then given two options: Create a New Group or Select an Existing Group. Make your selection and click the ">" to go to the next step.
Import the Contacts you'd like to add by either selecting them individually (checking off the check box to the right of their name) or adding 25 at a time with the Select Next 25 Contacts option.
Once all Contacts are selected, click ">" at the top to view the Group and send your Broadcast message.