The text in red under the message box are placeholders that use data from your data set to make each text personalized.
Press “Contact’s First Name” for example to automatically insert “@first_name@” into the message box. This means that for every text sent, it will display the first name of the contact where it says “@first_name@”, from the data set for the corresponding phone number. Press "More Placeholders" for more preset categories to insert and press help for all other options and more information on each placeholder.
Remember that each placeholder must exist as a column in your dataset and be labeled correctly when you are using the drop-up menus to name your columns when you are uploading your data set. For example; label your first name column “first_name” and use the @first_name@ placeholder in your message.