Twilio is required in order to utilize any of the SMS texting features available. SMS texting features include: SMS text Marketing, Transmitting orders to the Merchant via SMS text messaging, Order Acknowledgements, Assigning Orders to Delivery Drivers, SMS Driver Set-up etc...
Account Serial ID - Can be found on the main dashboard of your Twilio Account.
From Number - Can be found by Click on the # button on the left side of the Twilio dashboard.
Auth Token - Can be found in the main dashboard of your Twilio Account.