Vonage provides an API for sending SMS messages using its Messages API, which can be used to schedule messages to send at a later time. To do this, developers need a Vonage account and a virtual phone number, as well as Node.js. The Vonage CLI is used to create a new application and link the virtual phone number to it. A JavaScript file is then created to set up an Express app that handles POST requests for sending SMS messages, including scheduling them using node-cron. The app also includes front-end functionality in `index.html` to collect user input and send it to the back-end for processing.