I'm building a simple MEAN application, but facing some problem with a GET method.

I inserted some data in my mongo collection, now I want to GET all results passing it's Id as parameter, but angular is returning me the following:
[![enter image description here](https://i.stack.imgur.com/NgYv1.png)](https://i.stack.imgur.com/NgYv1.png)

I've searched about headers and httpParams, but can't seem to find a solution.
I tested on postman as well, using Get and passing a body as JSON, and it worked, I'm facing trouble sending it's body from angular

here's my code:

Angular service

```
  import { Injectable } from '@angular/core';
  import { HttpClient, HttpHeaders, HttpParams } from '@angular/common/http';
  import { Observable } from 'rxjs';
  import { map } from 'rxjs/operators';

  @Injectable({
    providedIn: 'root'
  })
  export class WebService {
    public api = "http://localhost:3000/";
    //NODE API
    public getRate(param: any){
      console.log(param);
      return this.http.get(this.api + "api/rate", {_id: param})
    }
}

```

NodeJs function

```
        module.exports.countVotes = function(req, res) {

        console.log(req.body._id);

        VoteModel.find({movie_id: req.body._id}, (err, rate) => {
            if(err){
                console.log('rate not found', err)
                return res.status(404).json({
                    message: 'failed to get movie rate'
                })
            } else {
                res.status(200).json(rate);
                console.log(rate);
            }
        })
    }

```

Node returns me req.body as undefined when called.
What am I missing? please someone help me.