The API allows you to send messages through your projects and services over HTTP/HTTPS, SMTP and SMPP protocols. Ready-made libraries in different programming languages connect to your project and help you send messages from anywhere with a single command. For simplified authorization, instead of a login and password pair, you can use a special API key.
https://smscentre.com/sys/send.php?login=alex&psw=123&phones=79999999999&mes=123456&tg=1
Examples of sending messages to Telegram