This is an example of how to build a console application in Visual Studio 2019 that uses the latest version of the Twilio NuGet package and works with legacy versions of the .NET Framework, such as .NET Framework 4.5.2, while maintaining compatibility with older Windows systems and operating systems. The project demonstrates how to code an application that can send SMS messages using a Twilio trial account and handles TLS 1.2 requirements for the Twilio API. The example also includes a case study project that covers obtaining Twilio credentials, creating a Visual Studio project, adding Twilio credentials to the project, installing the Twilio NuGet package, and testing the application.