To select your Audience in the SMS campaign, click the Select Audience option and you can choose between Collection, List, Copy & Paste, and File Upload.
In Collections and Lists, you can Select Target Audience using:
Existing Filters - Select based on existing filters or views
Create New Segment - Add new filters and select your conditions to create an audience
Once done, click Save to add selected contacts to your SMS campaign.
With Copy Paste, simply copy your contacts and paste them here to add them to your SMS campaign.
In File Upload, select only the .csv files to add your recipients to the SMS campaign.