To import contacts please upload a CSV file. You can find an example here.
The file can have the following information columns.
Match the type of information to the columns on your csv and click "Import Contacts". The list will be uploaded to the platform.
The APP ID column serves as the contact information for your messaging Apps. Each App has its own internal identification for users, for example WhatsApp uses something like (whatsap:+58583940355), Facebook uses a 16 digit number, and Telegram a 10 digit number.