c # – The wait method is marked (Get Web Api)

I have a web API that returns a json equivalent to my model, and the web works well api, the problem is that I can not read the json because the code is stopped in the line "wait". The URL I sent you is also correct.

The code is as follows:

static async public task GetCallAPI (string url)
{
try
{
using (client HttpClient = new HttpClient ())
{
string response = wait client.GetStringAsync (url);
if (answer! = null)
{
returns JsonConvert.DeserializeObject(reply);
}

}
}
catch (Exception ex)
{
MessageBox.Show (ex.Message);
}
return null;



}




private void button1_Click (object sender, EventArgs e)
{

string url = @ "http://memorygestionapi.azurewebsites.net/api/Company/GetTenantByRut?identifier=213854530015";

Data data = GetCallAPI (url) .Result;

label1.Text = data.Identifier;
label2.Text = data.RazonSocial;
label3.Text = data.FantasiaName;

}

}

Public class Data
{
public channel Identifier {get; together; }
public channel RazonSocial {get; together; }

public string NameFantasia {get; together; }

}