Continuing from the example in Your First Message Template, you can send your transactional message in php with the following.
<?php$url = "https://txnhog.co/txn/api/your_message_key";​$curl = curl_init($url);curl_setopt($curl, CURLOPT_URL, $url);curl_setopt($curl, CURLOPT_POST, true);curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);​$headers = array("Content-Type: application/x-www-form-urlencoded",);curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);​$data = "apiKey=sdkrjwhaldkgh3pwdfohawp4lyu&name=Shawn%20Spencer&phone=2085559988";​curl_setopt($curl, CURLOPT_POSTFIELDS, $data);​$resp = curl_exec($curl);curl_close($curl);var_dump($resp);?>