Заголовки пустые для curl php, пока я отправляю правильные заголовки

Question

Вот мой код

$str = json_encode($input);
                    $curl->setData($str);

                    $curl->http_header('MerchantKey', '*****');
                    $curl->http_header('Content-Type', 'application/json');
                    $curl->http_header('SecretToken', '************');

и вот что я получил в ответ

Curlphp Object
(
    [_curl:Curlphp:private] => 
    [_Url:Curlphp:private] => https://uatcp.hdfcergo.com/PCOnline/ChannelPartner/CalculatePremium
    [_method:Curlphp:private] => post
    [_Data:Curlphp:private] => {"ConfigurationParam":{"AgentCode":"FWC00070"},"VehicleMakeCode":"46","VehicleModelCode":"17431","RtoLocationCode":"10406","TypeOfBusiness":"NEW","PolicyType":"Comprehensive","CustomerType":"INDIVIDUAL","CustomerStateCode":"14","PurchaseRegistrationDate":"2020-02-06","RequiredIDV":0,"TPExistingEndDate":"1900-01-01","PospCode":"","AddOnCovers":{"IsZeroDepCover":"NO","IsTPPDDiscount":"NO","IsExLpgCngKit":"NO","IsLossOfUse":"NO","IsEmergencyAssistanceCover":"YES","IsNoClaimBonusProtection":"YES","IsEngineAndGearboxProtectorCover":"YES","IsCostOfConsumable":"YES","IsReturntoInvoice":"YES","IsEmergencyAssistanceWiderCover":"YES","NonelectricalAccessoriesIdv":0,"ElectricalAccessoriesIdv":0,"LpgCngKitIdv":"0","SelectedFuelType":"LPG","IsPAPaidDriver":"NO","PAPaidDriverSumInsured":0,"IsPAUnnamedPassenger":"NO","PAUnnamedPassengerNo":"3","IsLegalLiabilityDriver":"YES","PAPerUnnamedPassengerSumInsured":"0","LLPaidDriverNo":0,"IsLLEmployee":"NO","LLEmployeeNo":0,"IsTyreSecureCover":"YES","CpaYear":"1"}}
    [_options:Curlphp:private] => Array
        (
        )

    [_headers:Curlphp:private] => Array
        (
        )

    [_requestTimeout:Curlphp:private] => 0
    [_response:Curlphp:private] => 
    [_last_response:Curlphp:private] => {"Status":500,"UniqueRequestID":null,"Message":"Sorry, a technical error occurred! Please try again later.","Data":null}
    [_error_code:Curlphp:private] => 
    [_error_string:Curlphp:private] => 
    [_info:Curlphp:private] => Array
        (
            [url] => https://uatcp.hdfcergo.com/PCOnline/ChannelPartner/CalculatePremium
            [content_type] => application/json; charset=utf-8
            [http_code] => 200
            [header_size] => 171
            [request_size] => 1221
            [filetime] => -1
            [ssl_verify_result] => 0
            [redirect_count] => 0
            [total_time] => 0.061477
            [namelookup_time] => 0.004123
            [connect_time] => 0.007241
            [pretransfer_time] => 0.022082
            [size_upload] => 1007
            [size_download] => 120
            [speed_download] => 1951
            [speed_upload] => 16380
            [download_content_length] => -1
            [upload_content_length] => 1007
            [starttransfer_time] => 0.061364
            [redirect_time] => 0
            [redirect_url] => 
            [primary_ip] => 221.135.35.161
            [certinfo] => Array
                (
                )

            [primary_port] => 443
            [local_ip] => 172.18.0.5
            [local_port] => 45810
        )

)

Я не понимаю, в чем проблема, почему заголовки не задаются через curl, где в почтальоне Я могу получить ответ