If you cut and paste the following code into a web page and access it with a web browser, then a text message will be sent. Note that you should replace "<username>", "<password>" and "<mobile number>" with appropriate values.
Alternatively, here is a ZIP version of this code.
                        
                        <html>
                        <body>
                        <?php
                function sendTextMessage ($username, $password, $message, $destination) {
                                
                        $host="https://www.totext.net/";
                        $path="selfcare/com/zipzaptext/selfcare/";
                        $action="SendMessagesApi.action";
                                
                        $url = $host.$path.$action;
                        $ch = curl_init();
                        curl_setopt($ch, CURLOPT_URL, $url);
                        curl_setopt ($ch, CURLOPT_POST, 1);
                                
                        $vars = array();
                        $vars["destination"]= $destination;
                        $vars["username"]= $username;
                        $vars["password"]= $password;
                        $vars["message"] = $message;
                                
                        curl_setopt ($ch, CURLOPT_POSTFIELDS, $vars);
                        curl_exec ($ch);
                        curl_close ($ch);
                }
                        ?>
                                
                        Test results:<br>
                        <?php
                            sendTextMessage ("<username>", "<password>", "Test from PHP", "<mobile number>");
                        ?>
                        
                        </body>
                        </html>
                        
                        
We're very keen that your integration should be straightforward and easy, so if you're having any trouble at all, then please don't hesitate to get in touch.