How to integrate sending SMS (text messages) to your app with Twilio

Twilio is a service that lets your app send and receive SMS just like a phone, but through the internet. You get a Twilio phone number, and when someone texts it, Twilio forwards the message to your app’s web address so you can read it and respond automatically. Your app can also send texts (alerts, reminders, OTPs) to any mobile number using Twilio’s simple tools—no telecom contracts needed.

Example: A delivery app texts customers “Your order is arriving in 10 minutes,” and if the customer replies “Delay,” the app receives that message via Twilio and updates the delivery time.

Integrate SMS sending with Twilio.

Requirements:
– Backend API `/api/send-sms` using Twilio SDK.
– Env vars for Twilio SID + token.
– Function `sendSMS(to, message)` that sends an SMS.
– Frontend: simple form (phone number, message, "Send" button).
– Store SMS logs in `sms_logs (id, to, message, status, created_at)`.
– Output: complete Twilio integration with testable flow.