Symfony 4 : DataFixtures directory not found

I'am using symfony 4

I have created an make called Ad:entity with this commande php bin/console make:entity

Ad.php

<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
* @ORM\Entity(repositoryClass="App\Repository\AdRepository")
*/
class Ad
{
 /**
 * @ORM\Id()
 * @ORM\GeneratedValue()
 * @ORM\Column(type="integer")
 */
private $id;

/**
 * @ORM\Column(type="string", length=255)
 */
private $title;

/**
 * @ORM\Column(type="string", length=255)
 */
private $slug;

/**
 * @ORM\Column(type="float")
 */
private $price;

/**
 * @ORM\Column(type="text")
 */
private $introduction;

/**
 * @ORM\Column(type="text")
 */
private $content;

/**
 * @ORM\Column(type="string", length=255)
 */
private $coverImage;

/**
 * @ORM\Column(type="integer")
 */
private $rooms;

public function getId(): ?int
{
    return $this->id;
}

public function getTitle(): ?string
{
    return $this->title;
}

public function setTitle(string $title): self
{
    $this->title = $title;

    return $this;
}

public function getSlug(): ?string
{
    return $this->slug;
}

public function setSlug(string $slug): self
{
    $this->slug = $slug;

    return $this;
}

public function getPrice(): ?float
{
    return $this->price;
}

public function setPrice(float $price): self
{
    $this->price = $price;

    return $this;
}

public function getIntroduction(): ?string
{
    return $this->introduction;
}

public function setIntroduction(string $introduction): self
{
    $this->introduction = $introduction;

    return $this;
}

public function getContent(): ?string
{
    return $this->content;
}

public function setContent(string $content): self
{
    $this->content = $content;

    return $this;
}

public function getCoverImage(): ?string
{
    return $this->coverImage;
}

public function setCoverImage(string $coverImage): self
{
    $this->coverImage = $coverImage;

    return $this;
}

public function getRooms(): ?int
{
    return $this->rooms;
}

public function setRooms(int $rooms): self
{
    $this->rooms = $rooms;

    return $this;
}
}

And i want to use a package : orm-fixtures

so i runed this command : composer require orm-fixtures --dev

But i don't see the DataFixtures in my project folder, screenshot : https://user.oc-static.com/upload/2019/11/01/15726034821433_Screenshot%20from%202019-11-01%2011-12-38.png