Error on choosing the element in the form webform builder

Problem/Motivation

The ajax popup isn't working anymore as soon as the module is activated;
Error in log:
TypeError: Drupal\webform_remote_fields\Service\WebformRemoteFieldHelper::buildEndpointUrl(): Argument #1 ($endpoint) must be of type string, null given, called in /app/web/modules/contrib/webform_remote_fields/src/Traits/RemoteFieldBaseTrait.php on line 82 in Drupal\webform_remote_fields\Service\WebformRemoteFieldHelper->buildEndpointUrl() (line 156 of /app/web/modules/contrib/webform_remote_fields/src/Service/WebformRemoteFieldHelper.php).

Error shows as in screen shot

In line 82 WebformRemoteFieldHelper->buildEndpointUrl() needs a string and gets a NULL.
This value is build in line 54 $apiSettings = $wrHelperService->extractElementSettings($element, $formState);
in the method: extractElementSettings($element, $formState);
from Service/WebformRemoteFieldHelper, line 346
$apiEndpoint is set to NULL if $element['#api_endpoint'] not set;
LINE 348 $apiEndpoint = $element['#api_endpoint'] ?? NULL;
Setting this to
LINE 348 $apiEndpoint = $element['#api_endpoint'] ?? "";
Seems to work for me...

Steps to reproduce

Drupal core 10.4.7
Webform 6.2.9
Webform Remote Fields 2.0.1
PHP 8.4.1

Proposed resolution

Replace NULL by "" in function extractElementSettings. line 348

  /**
   * Extract setting of the Webform remote field element.
   *
   * The order of array with the setting values.
   *  -> api_endpoint_add_query_parameter.
   *  -> api_endpoint.
   *  -> api_result_select_text.
   *  -> headers.
   *
   * @param array $element
   *   The webform element.
   * @param \Drupal\Core\Form\FormStateInterface $formState
   *   An object of the form state.
   *
   * @return array
   *   Array with the key => value setting.
   */
  public function extractElementSettings(array $element, FormStateInterface $formState): array {
    $apiEndpointAddQueryParameter = $element['#api_endpoint_add_query_parameter'] ?? FALSE;
    $apiEndpoint = $element['#api_endpoint'] ?? "";
    $apiResultSelectValue = $element['#api_result_select_value'] ?? NULL;
    $apiResultSelectText = $element['#api_result_select_text'] ?? NULL;
    $apiNeedsHeader = $element['#needs_header'] ?? NULL;
    $rootPropertyPath = $element['#root_property_path'] ?? NULL;

    $custom_headers = [];
    if ($apiNeedsHeader) {
      $custom_headers = Yaml::parse($element['#headers']);
    }

    // As we have the support for get the property request value from,
    // another webform field. We have to replace the tokens for
    // #api_result_select_value setting at this point.
    if (!empty($element['#api_result_select_value'])) {
      $apiResultSelectValueToken = $this->token->replace(
        $element['#api_result_select_value'],
        ['form_value' => $formState->getValues()],
      );
      if ($apiResultSelectValueToken) {
        $apiResultSelectValue = $apiResultSelectValueToken;
      }
    }

    return [
      'api_endpoint_add_query_parameter' => $apiEndpointAddQueryParameter,
      'api_endpoint' => $apiEndpoint,
      'root_property_path' => $rootPropertyPath,
      'api_result_select_value' => $apiResultSelectValue,
      'api_result_select_text' => $apiResultSelectText,
      'custom_headers' => $custom_headers,
      'needs_header' => $apiNeedsHeader,
      'api_round_result' => $element['#api_round_result'] ?? 0,
    ];
  }

Remaining tasks

User interface changes

API changes

Data model changes