Alamofire 4.3 can't send JSON request - ios

Question

Iam Trying to send a JSON request using Alamofire but it's not working as a JSON Request here's my JSON :
{"ClientID":"55050","AdminId":"myemail","Password":"123"}
content-type → application/json; charset=utf-8
and here's my code :
import Alamofire
func doLogin(username:String ,password:String) {
let parameters = ["ClientID":"55050" , "AdminId":username,"Password":password]
Alamofire.request("myurl.com", method: .post, parameters: parameters, encoding: JSONEncoding(options: []) ).responseJSON(completionHandler: {
response in
print(response)
})
and here's the response which i am getting
FAILURE: responseSerializationFailed(Alamofire.AFError.ResponseSerializationFailureReason.jsonSerializationFailed(Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 3." UserInfo={NSDebugDescription=Invalid value around character 3.}))

Answer 1

By reading the documentation i just need to put header to set the request as application/json
so i added extra parameter header :
let headers: HTTPHeaders = [
"Authorization": "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==",
"Accept": "application/json"
]
Alamofire.request(ApiKeys().login, method : .post , parameters : parameters, encoding: JSONEncoding.default , headers: headers).responseJSON { response in
}
and now it's working perfectly thanks everyone for trying to help :)

Answer 2

It seems you must have missed header in your request. So, there has been no response.
Your header must be a dictionary [String: String].
let header = ["Content-Type" : "application/json"]
And your sample request should be:
Alamofire.request(getCategoryPath, method: .post, parameters: parameters, encoding: URLEncoding.default, headers: header)
.responseJSON { response in
guard response.result.error == nil else {
print(response.result.error!)
}
print(response.result.value)
}