FedEx APIs : Getting error while creating shipment

I have two payloads on giving me success response and also give me label pdf url and in another payload i am getting internal server error

this is both payload :

success payload :

{
    "accountNumber": {
        "value": "ACCOUNT_NUMBER"
    },
    "labelResponseOptions": "URL_ONLY",
    "requestedShipment": {
        "blockInsightVisibility": false,
        "labelSpecification": {
            "imageType": "PDF",
            "labelStockType": "PAPER_85X11_TOP_HALF_LABEL"
        },
        "packagingType": "YOUR_PACKAGING",
        "pickupType": "DROPOFF_AT_FEDEX_LOCATION",
        "recipients": [
            {
                "address": {
                    "city": "DUBAI",
                    "countryCode": "AE",
                    "postalCode": "00000",
                    "stateOrProvinceCode": "DU",
                    "streetLines": [
                        "RECIPIENT STREET LINE 1",
                        "RECIPIENT STREET LINE 2"
                    ]
                },
                "contact": {
                    "companyName": "Recipient Company Name",
                    "personName": "RECIPIENT NAME",
                    "phoneNumber": 1234567890
                }
            }
        ],
        "requestedPackageLineItems": [
            {
                "declaredValue": {
                    "amount": 100,
                    "currency": "DHS"
                },
                "itemDescriptionForClearance": "Item description for clearance",
                "weight": {
                    "units": "KG",
                    "value": 10
                }
            }
        ],
        "serviceType": "STANDARD_OVERNIGHT",
        "shipDatestamp": "2024-03-07",
        "shipper": {
            "address": {
                "city": "SHARJAH",
                "countryCode": "AE",
                "postalCode": "00000",
                "stateOrProvinceCode": "SH",
                "streetLines": [
                    "SHIPPER STREET LINE 1"
                ]
            },
            "contact": {
                "companyName": "Shipper Company Name",
                "personName": "SHIPPER NAME",
                "phoneNumber": 1234567890
            }
        },
        "shippingChargesPayment": {
            "paymentType": "SENDER"
        }
    }
}

Error payload :

{
    "accountNumber": {
        "value": "ACCOUNT_NUMBER"
    },
    "labelResponseOptions": "URL_ONLY",
    "requestedShipment": {
        "blockInsightVisibility": false,
        "labelSpecification": {
            "imageType": "PDF",
            "labelStockType": "PAPER_85X11_TOP_HALF_LABEL"
        },
        "packagingType": "YOUR_PACKAGING",
        "pickupType": "DROPOFF_AT_FEDEX_LOCATION",
        "recipients": [
            {
                "address": {
                    "city": "SHARJAH",
                    "countryCode": "AE",
                    "postalCode": "00000",
                    "stateOrProvinceCode": "SH",
                    "streetLines": [
                        "street lines"
                    ]
                },
                "contact": {
                    "companyName": "company",
                    "personName": "recipient",
                    "phoneNumber": 1234567890
                }
            }
        ],
        "requestedPackageLineItems": [
            {
                "declaredValue": {
                    "amount": 100,
                    "currency": "DHS"
                },
                "itemDescriptionForClearance": "Camera",
                "weight": {
                    "units": "KG",
                    "value": 10
                }
            }
        ],
        "serviceType": "STANDARD_OVERNIGHT",
        "shipDatestamp": "2024-08-12",
        "shipper": {
            "address": {
                "city": "DUBAI",
                "countryCode": "AE",
                "postalCode": "00000",
                "stateOrProvinceCode": "DU",
                "streetLines": [
                    "street lines"
                ]
            },
            "contact": {
                "companyName": "company",
                "personName": "Shipper",
                "phoneNumber": 1234567890
            }
        },
        "shippingChargesPayment": {
            "paymentType": "SENDER"
        }
    }
}

this is endpoint /v1/shipments

my techstack is :

NextJS with Typescript in backend made using .net APIs.

(note: i use backend for calling fedex apis)