Multi-part formdata working with Alamofire but failing with URLSession

I am trying to make an api request which type is "multipartFormData", is working completely fine with Alamofire but getting failed when uisng URLSession

Alamofire

   func alamoFire(){

        let operatorID = "24601"
        let custName = "PEp"
        let dcName = "Richasox"
        let bucketName = "s3BucketXXX"
        
        let headers: HTTPHeaders = [
            "Content-type": "multipart/form-data",
            "x-api-key" : "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
        ]

        AF.upload(
            multipartFormData: { multipartFormData in
                multipartFormData.append(operatorID.data(using: .utf8)!, withName: "pickerId")
                multipartFormData.append(dcName.data(using: .utf8)!, withName: "dcName")
                multipartFormData.append(custName.data(using: .utf8)!, withName: "custName")
                multipartFormData.append(bucketName.data(using: .utf8)!, withName: "bucketName")

            },
            to: "https://xxx.us-east-2.amazonaws.com/endpoint", method: .post , headers: headers)
            .validate(statusCode: 200..<300)
            .response { resp in
                switch resp.result{
                case .failure(let error):
                    print(error)
                case.success( _):
                    print("Response after upload Img: \(resp.result)")
                }
            }
    }

URLSession

func urlSession() {
    
    let operatorID = "24601"
let custName = "PEPSI%20CORPORATE"
let dcName = "Richardson%20DC"
let bucketName = "picker-images-upload-rehrig"

let url = URL(string: "https://xxx.us-east-2.amazonaws.com/endpoint")
let boundary = UUID().uuidString
let session = URLSession.shared
var urlRequest = URLRequest(url: url!)
urlRequest.httpMethod = "POST"
urlRequest.setValue("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", forHTTPHeaderField: "x-api-key")
urlRequest.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

var data = Data()
data.append("\r\n--\(boundary)\r\n".data(using: .utf8)!)
data.append("Content-Disposition: form-data;pickerId=\"\(operatorID)\"; dcName=\"\(dcName)\"; bucketName=\"\(bucketName)\"; custName=\"\(custName)\"\r\n".data(using: .utf8)!)
data.append("\r\n".data(using:.utf8)!)

session.uploadTask(with: urlRequest, from: data, completionHandler: { responseData, response, error in
    if error == nil {
        let jsonData = try? JSONSerialization.jsonObject(with: responseData!, options: .allowFragments)
        if let json = jsonData as? [String: Any] {
            print("picker resp",json)
            
        }
    }
}).resume()

}

Error when using URLSession

Optional<NSURLResponse>
  - some : <NSHTTPURLResponse: 0x283f8f4a0> { URL: https://xxx.us-east-2.amazonaws.com/endpoint } { Status Code: 502, Headers {
    "Content-Length" =     (
        36
    );
    "Content-Type" =     (
        "application/json"
    );
    Date =     (
        "Sat, 15 Jan 2022 16:57:05 GMT"
    );
    Via =     (
        "1.1 62f7aa308c367fb8f14fc57f199056cc.cloudfront.net (CloudFront)"
    );
    "x-amz-apigw-id" =     (
        "L_xzJGBIiYcFfAA="
    );
    "x-amz-cf-id" =     (
        "2M2PlnPLZ8k_91htcX4OM4UL2a5ldOfntUbVO3xxMp702m9MMr0Elw=="
    );
    "x-amz-cf-pop" =     (
        "BLR50-C3"
    );
    "x-amzn-errortype" =     (
        InternalServerErrorException
    );
    "x-amzn-requestid" =     (
        "b7de8e82-06fe-41e0-9deb-0f2783aeea89"
    );
    "x-cache" =     (
        "Error from cloudfront"
    );
} }