如何使用CURL发送数组？

$array = array('key1' => 'value1', 'key2' => 'value2');
$json_data = json_encode($array);

$url = 'https://example.com/api/endpoint';
$ch = curl_init($url);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $json_data);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'Content-Type: application/json',
    'Content-Length: ' . strlen($json_data))
);

$response = curl_exec($ch);
curl_close($ch);