I am configuring a login in Angular 17 in which I am using userStorageService but when I want to store the user there it generates this error

Argument of type ‘Object’ is not assignable to parameter of type ‘string’

this is my code

import { HttpClient, HttpHeaders } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable, map } from 'rxjs';
import { UserStorageService } from '../storage/user-storage.service';


const BASIC_URL = "http://localhost:8080/"

@Injectable({
  providedIn: 'root'
})
export class AuthService {

  constructor(private http: HttpClient,
    private userStorageService: UserStorageService
  ) { }

  register(signupRequest:any): Observable<any>{
    return this.http.post(BASIC_URL+"sign-up", signupRequest);
  }

  login(username: string, password:string):any{
    const headers = new HttpHeaders().set('Content-Type', 'application/json');
    const body = {username, password};

    return this.http.post(BASIC_URL + 'authenticate', body, {headers, observe: 'response'}).pipe(
      map((res)=>{
        const token = res.headers.get('authorization').substring(7);
        const user = res.body;
        if(token && user){
          this.userStorageService.saveToken(token);
          this.userStorageService.saveUser(user);
          return true;
        }
        return false;
      })

    );
  }
}

I have already checked the imports and everything but I don’t know what is wrong