how can i extract the credentials from authorization header in Node js

Question

Angular

auth.service.ts

login(mobileNumber: number, password: string) {
    console.log(mobileNumber,password);
    let headers = new HttpHeaders({'Content-Type': 'application/json','Authorization': 'Basic '+window.btoa(mobileNumber + ':' + password) });
    let options = { headers: headers };
    return this.http.post<>("http://localhost:3000/api/user/login",{}, options)
     }

Node js

User.js

router.post("/login", (req, res, next) => {
let user = basicAuth(req);
 console.log("mobile number is ",user.name);
});

Error Message : TypeError: Cannot read property 'name' of undefined