public loginuser(username : String , password :  String){
      const body = {
          username : username,
          password : password,
      }

      var reqHeader = new HttpHeaders({'No-Auth':'True' });
      return this.http.post(this.rootUrl + '/access/login', body ,{ headers: reqHeader });
}

OnSubmit(form: NgForm){

       this.userService.loginuser(this.username,this.password).subscribe(
           (data : any)=>{
               console.log(data);
               localStorage.setItem('userToken',data.token);
               this.router.navigate(['/login']);
           },
           (err : HttpErrorResponse)=>{
               console.log(err.error);
           }
       );
   }

http code : 201
{token : "the token"}

http code : 404
{
    "status_code":31,
    "status_message":"Username or password invalid"
}