如何向我的Angular帖子请求添加标题？

对于学校项目,我需要使用Angular创建一个简单的登录页面.单击登录按钮时,我需要在帖子中添加Authorization标头.我创建了一个后端,当我使用邮递员将我的授权值发布到该后端时,它的工作方式与后端没有任何问题.当我尝试使用我的前端发布到同一个后端时,它不起作用.向帖子添加标题的最佳方法是什么？似乎意见分歧.这是我的代码：

export class LoginComponent{
    title = 'Login';
    email = '';
    password = '';
    credentials = '';
    basic = '';
    constructor(private http:HttpClient){

    }

    createAuthorizationHeader(headers:Headers,basic){
        headers.append('Authorization',basic);
    }

    login(event){
        this.email = (<HTMLInputElement>document.getElementById("email")).value;
        this.password = (<HTMLInputElement>document.getElementById("password")).value;
        this.credentials = this.email + ":" + this.password;
        this.basic = "Basic " + btoa(this.credentials);
        console.log(this.basic);
        let headers = new Headers();
        headers.append('Content-Type','application/json');
        headers.append('Authorization',this.basic);
        let options = new RequestOptions({headers:headers});
        console.log(headers);
        return this.http.post('http://localhost:8000/api/v1/authenticate',options)
        .subscribe(
            res =>{
                console.log(res);
            },err => {
                console.log(err.message);
            }
        )
    }
}

当我运行该代码时,我得到400状态响应并且不添加标头.

return this.http.post('http://localhost:8000/api/v1/authenticate',null,options);

let headers = new HttpHeaders({
    'Content-Type': 'application/json','Authorization': this.basic });
let options = { headers: headers };