public function sendSMS($f3)
{
// Set response type
header('Content-type: application/json');
// Send SMS
try {
$sentMessages = SMS::createAndSend(['recipient_phone_number' => $f3->get('POST.recipient_phone_number'), 'message_content' => $f3->get('POST.message_content')]);
echo json_encode(['status' => 'OK', 'number_of_messages_sent' => $sentMessages]);
} catch (Exception $e) {
echo json_encode(['status' => 'ERR', 'cause' => $e->getMessage()]);
}
}