🇱🇹Lithuania @aliaric

I have an issue:
Code:

          $form['vocabulary_' . $category->tid] = [
            '#title' => $this->t('You will add these tags'),
            '#prefix' => '<h2>' . $category->name . '</h2>',
            '#type' => 'entity_autocomplete_tagify',
            '#target_type' => 'taxonomy_term',
            '#tags' => TRUE,
            '#selection_handler' => 'default',
            '#selection_settings' => [
              'target_bundles' => ['tags'],
              'bundle' => ('tags'),
            ],
            '#autocreate' => [
              'bundle' => 'tags',
            ],
            '#description' => $this->t('for all documents below simultaneously'),
            '#wrapper_attributes' => [
              'id' => 'odt-filter',
              'class' => ['container-inline'],
            ],
            '#max_items' => 10,
            '#suggestions_dropdown' => 1,
            '#match_operator' => 'CONTAINS',
            '#show_entity_id' => 0,
            '#identifier' => 'vocabulary_' . $category->tid,
          ];

I'm not quite sure what '#identifier' is
version: '1.2.15+3-dev'
php: 8.1.27
drupal: 10.2.2
Errors:

TypeError: preg_match(): Argument #2 ($subject) must be of type string, array given in preg_match() (line 207 of ...
...\core\lib\Drupal\Core\Routing\UrlGenerator.php).

and
Warning: Undefined array key "#placeholder" in Drupal\tagify\Element\EntityAutocompleteTagify::processEntityAutocompleteTagify() (line 152 of ...\modules\contrib\tagify\src\Element\EntityAutocompleteTagify.php)