Alan Heikkila
--- a/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+++ b/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+      ],
+      '#submit'  => [
+        [$this, 'submitRevertDefaults'],
+      ],
    ];
+
    return $actions;
  }

+  /**
+   * Ajax callback to cancel discard changes.
+   *
+   * @return \Drupal\Core\Ajax\AjaxResponse
+   *   An ajax response object.
+   */
+  public function ajaxCallbackDiscardChanges() {
-  public function ajaxCallbackDiscardChanges() {
+  public function ajaxCallbackDiscardChanges(): AjaxResponse {
--- a/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+++ b/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+    $settings = [
+      'title'     => $this->t('Discard changes'),
+      'modal'     => TRUE,
+      'resizable' => TRUE,
+    ];
+    $command = new OpenModalDialogWithUrl($url->toString(),
+      $settings);
+    $response->addCommand($command);
+
+    return $response;
+  }
+
+  /**
+   * Non Ajax redirect to discard changes form.
+   */
+  public function submitDiscardChanges(array $form, FormStateInterface $form_state) {
-  public function submitDiscardChanges(array $form, FormStateInterface $form_state) {
+  public function submitDiscardChanges(array $form, FormStateInterface $form_state): void {
--- a/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+++ b/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+   */
+  public function submitDiscardChanges(array $form, FormStateInterface $form_state) {
+    // Generate the URL using the sectionStorage's getLayoutBuilderUrl method.
+    $url = $this->sectionStorage->getLayoutBuilderUrl('discard_changes');
+
+    // Set the redirect to the generated "Discard changes" page.
+    $form_state->setRedirectUrl($url);
+  }
+
+  /**
+   * Ajax callback to Revert defaults .
+   *
+   * @return \Drupal\Core\Ajax\AjaxResponse
+   *   An ajax response object.
+   */
+  public function ajaxCallbackRevertDefaults() {
-  public function ajaxCallbackRevertDefaults() {
+  public function ajaxCallbackRevertDefaults(): AjaxResponse {
--- a/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+++ b/core/modules/layout_builder/src/Form/OverridesEntityForm.php
+      'modal'     => TRUE,
+      'resizable' => TRUE,
+    ];
+    $command = new OpenModalDialogWithUrl($url->toString(),
+      $settings);
+    $response->addCommand($command);
+
+    return $response;
+  }
+
+  /**
+   * Non Ajax redirect to "Revert defaults" form.
+   *
+   * We need this one if our javascript doesn't work for some reason.
+   */
+  public function submitRevertDefaults(array $form, FormStateInterface $form_state) {
-  public function submitRevertDefaults(array $form, FormStateInterface $form_state) {
+  public function submitRevertDefaults(array $form, FormStateInterface $form_state): void {
--- a/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockTest.php
+++ b/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockTest.php
  /**
   * Provides test data for ::testNoLayoutSave().
   */
-  public static function layoutNoSaveProvider() {
+  public static function layoutNoSaveProvider():array {