如何使用paypal-PHP-sdk进行负面测试.我尝试将标头添加到api上下文,但始终收到此响应：

{
    "name": "INVALID_NEGATIVE_testING_INPUT","message": "Invalid input found. See the following supported cases.","links": [
        {
            "href": "https://develoPEr.paypal.COM/docs/api/nt-rest/","rel": "information_link"
        }
    ],"details": [
        {
            "issue": "You must use a valid URL supported by negative testing."
        }
    ]
}

我发了标题

PayPal-Mock-Response: {"mock_application_codes":"AUTHORIZATION_VOIDED"}

在我的PHP代码中

$i_header["header"] = "PayPal-Mock-Response";
    $i_header["value"] = json_encode(["mock_application_codes" => "INSTRUMENT_DECLINED"]);

    $o_apiContext->addRequestHeader($i_header["header"],$i_header["value"]);

测试输入的完整列表
https://developer.paypal.com/docs/api/payments/#errors

有什么建议？谢谢

$apiContext->addRequestHeader("PayPal-Mock-Response","{'mock_application_codes':'INSTRUMENT_DECLINED'}");