Drupal - How to make EntityListBuilder sortable?

This is how i sort my entityListBuilder :

i use the method load() :

  public function load() {

    $entity_query = \Drupal::service('entity.query')->get('produits_entity');
    $header = $this->buildHeader();

    $entity_query->pager(50);
    $entity_query->tableSort($header);

    $uids = $entity_query->execute();

    return $this->storage->loadMultiple($uids);
  }

Then i build my header like this :

  /**
   * {@inheritdoc}
   */
  public function buildHeader() {

    $header = array(
        'id' => array(
            'data' => $this->t('N° produit'),
            'field' => 'id',
            'specifier' => 'id',
            'class' => array(RESPONSIVE_PRIORITY_LOW),
        ),
        'nom' => array(
            'data' => $this->t('Nom'),
            'field' => 'name',
            'specifier' => 'name',
        ),

        'prixHT' => array(
            'data' => $this->t('Prix HT'),
            'field' => 'prixHT',
            'specifier' => 'prixHT',
        ),

        'statut' => array(
            'data' => $this->t('Actif'),
            'field' => 'actif',
            'specifier' => 'actif',
        ),

    );

    return $header + parent::buildHeader();
  }

you need to add in your buildHeader() 2 param for each field you want sort :

name of field and specifier

Entity query doesn't have tablesort integration. You'd have to implement the query logic yourself.

For content entities, I would strongly recommend to rely on the views integration instead. List builders are limited in functionality and mostly useful for config entities only.