Не проходит авторизация

Всем салют!

Не получается авторизоваться пост запросом из этой ссылки:

import requests
import time

if __name__ == "__main__":
    try:
        s = requests.session()
        headers = {
            
            'Content-Type': 'application/json',
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36',
            'ForceUseSession': 'true'
        }
        data={'UserName': 'Login', 'UserPassword': 'Password'}
        p = s.post('https://mysite.ru/ServiceModel/AuthService.svc/Login', headers=headers, data=data)
        s.cookies
        print(p.text)
    except Exception as e:
            print(f"\n\n\n\n{e}\n\n\n")
        
time.sleep(50)

Возвращает такую ошибку:

requests.packages.urllib3.connectionpool - DEBUG - "POST /Login HTTP/1.1" 400 3069
<?xml version="1.0" encoding="utf-8"?>


  
    Request Error
  
  
    
      
Request Error
      
The server encountered an error processing the request. The exception message is 'There was an error checking start element of object of type Core.ServiceModelContract.AuthToken. Encountered unexpected character 'U'.'. See server logs for more details. The exception stack trace is: 
      
   at System.Runtime.Serialization.XmlObjectSerializer.IsStartObjectHandleExceptions(XmlReaderDelegator reader)
   at System.ServiceModel.Dispatcher.SingleBodyParameterMessageFormatter.ReadObject(Message message)
   at System.ServiceModel.Dispatcher.SingleBodyParameterDataContractMessageFormatter.ReadObject(Message message)
   at System.ServiceModel.Dispatcher.SingleBodyParameterMessageFormatter.DeserializeRequest(Message message, Object[] parameters)
   at System.ServiceModel.Dispatcher.DemultiplexingDispatchMessageFormatter.DeserializeRequest(Message message, Object[] parameters)
   at System.ServiceModel.Dispatcher.UriTemplateDispatchFormatter.DeserializeRequest(Message message, Object[] parameters)
   at System.ServiceModel.Dispatcher.DispatchOperationRuntime.DeserializeInputs(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11(MessageRpc& rpc)
   at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)