IONIC 3-4 HTTP HEADERT

I'm doing a GET request with header, which has basic Auth, I'm getting the following error

link

it seems that it is not sent

let token =  "Basic ************=";
    let headers = new HttpHeaders({ 
      "Content-Type": "application/json",
      "Authorization": token
  });
    const url='url'


    this.http.get(url,{headers}).subscribe((res) => {
      console.log(res);


    })