Cant create WAF rule

I trying create the rule Скриншот 18-05-2022 17:56:51.jpg through PHP API library:

use Cloudflare\API\Auth\APIKey;
use Cloudflare\API\Adapter\Guzzle;

$adapter = new Guzzle(new APIKey($conf['email'], $conf['key']));

$adapter->post("zones/$zoneId/firewall/rules", [
    [
        'action' => 'allow',
        'filter' => [
            'expression' => '(http.user_agent contains "yandex")'
        ]
    ]
]);

Got error filter at index (0) conflicts with an existing filter.
But my domain dont have any rules Скриншот 18-05-2022 17:56:51.jpg.