Unity Web Request Post

Question

I am trying to post request via UnityWebRequest.Post method but got this error

"Curl error 1: Received HTTP/0.9 when not allowed".

Below mentioned is my code:

WWWForm form = new WWWForm();
form.AddField("username", userName);
form.AddField("password", password);

using (UnityWebRequest webRequest = UnityWebRequest.Post("http://193.16.117.212:48080/login", form))
{
    yield return webRequest.SendWebRequest();

    if (webRequest.result != UnityWebRequest.Result.Success)
    {
        Debug.Log(webRequest.error);
    }
    else
    {
        Debug.Log("Form upload complete");
    }
}

Can someone please help?