Customize or Personalize - You can send messages with multiple variables in the message Ex. First Name, Last Name etc. Create an excel file with all data available in multiple fields. One customer data should be in one raw ex. Mobile number, First Name, Last Name etc. Once you upload the file you will get choose to select the fields which contain the number, Other fields will be visible in Message you can select the fields wherever you want to merge in the message. Files supported are XLSX, CSV. The first column of excel file contains the numbers.