Can't select related objects?

Question

Doctrine ORM

class Digest
{
...
/**
     * @ORM\ManyToMany(targetEntity="Category")
     * @ORM\JoinTable(
     *     name="digest_category",
     *     joinColumns={
     *          @JoinColumn(name="digest_id", referencedColumnName="id")},
     *          inverseJoinColumns={
     *              @JoinColumn(name="category_id", referencedColumnName="id")}
     * )
     */
    private $category;
 ...
}

A third join table is created (many-to-many)
Next...
I expect to get related objects, but no.
Fatal error: Uncaught Error: Call to undefined method Doctrine\ORM\PersistentCollection::getName() in D:\OpenServer\OSPanel\domains\catalog\api\Controller\DigestController.php on line 28

$repository = new RepositoryDigest($this->em);
        $data = $repository->getOne($id);
        $category  = $data->getCategory();
        $name = $category->getName();

True, I didn't map in the "Category" entity.
Probably the question is,
How to get child elements with "Manny to Manny" relationships?
It turns out that the entity "Category" does not know about the existence of the entity "Digest"