Whats Happening?

"https://ttsfree.com/api/v1/tts", CURLOPT_RETURNTRANSFER => true, CURLOPT_ENCODING => "", CURLOPT_MAXREDIRS => 10, CURLOPT_TIMEOUT => 30, CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1, CURLOPT_CUSTOMREQUEST => "POST", CURLOPT_POSTFIELDS => $post_data, CURLOPT_HTTPHEADER => array( "apikey:9192017521df438eacec62cf6f126c30", "content-type: application/json" ), )); $response = curl_exec($curl); $err = curl_error($curl); curl_close($curl); if ($err) { echo "cURL Error #:" . $err; } else { // echo $response; $data = json_decode($response,true); $wave_mp3 = base64_decode($data['audioData']); echo $wave_mp3; } ?>