this is context definition

app/docroot/modules/custom/contDef/contentDef.info.yml

+name: Cont def. task
+package: Custom
+type: module
+core_version_requirement: ^8.8 || ^9

app/docroot/modules/custom/contDef/src/Plugin/Block/ContBlock.php

+<?php
+
+
+namespace Drupal\contDef\Plugin\Block;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\Context\EntityContext;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\media\Entity\Media;
+use Drupal\file\Entity\File;
+
+/**
+ * Provides a 'ContDef' Block.
+ *
+ * @Block(
+ *   id = "cont_definition_block",
+ *   admin_label = @Translation("ContDef block"),
+ *   category = @Translation("ContDefBlock"),
+ * )
+ */
+
+class ContBlock extends BlockBase
+{
+  /**
+   * {@inheritdoc}
+   */
+  public function build(){
+    $context = EntityContext::fromEntityType(\Drupal::entityTypeManager()->getDefinition('user'));
+  }
+}

app/docroot/modules/custom/localtask/src/Controller/DrupalLocalTask.php

@@ -30,6 +30,8 @@ public function swapi($node){
   $id = $node->get('field_swapi_id')->value;
   $conc = 'https://swapi.dev/api/'.$type.'/'.$id.'/';
   $request = $this->getResult($conc);
+ // $request = json_encode($request);
+
   return [
     '#markup' => $request,
   ];

app/docroot/modules/custom/testblocklast/src/Plugin/Block/ConBlock.php

+<?php
+
+namespace Drupal\testblocklast\Plugin\Block;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Session\AccountInterface;
+use Psr\Container\ContainerInterface;
+
+/**
+ * Provides a 'Text' Block.
+ *
+ * @Block(
+ *   id = "testblocklast_text_block_block",
+ *   admin_label = @Translation("Text block last"),
+ *   category = @Translation("TestLastBlock"),
+ *   context_definitions = {
+ *     "node" = @ContextDefinition("entity:node", required = FALSE, label = @Translation("Node")),
+ *     "term" = @ContextDefinition("entity:taxonomy_term", required = FALSE, label = @Translation("Term"))
+ *   }
+ * )
+ */
+class ConBlock extends BlockBase{
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    $output = '';
+    $node = $this->getContextValue('node');
+    $term = $this->getContextValue('term');
+    if ($node != null){
+      $view_builder = \Drupal::entityTypeManager()->getViewBuilder('node');
+      $rss_output = $view_builder->view($node, 'teaser');
+      $output = \Drupal::service('renderer')->render($rss_output);
+    }
+    else {
+      $view_builder = \Drupal::entityTypeManager()->getViewBuilder('taxonomy_term');
+      $rss_output = $view_builder->view($term, 'teaser');
+      $output = \Drupal::service('renderer')->render($rss_output);
+    }
+
+    return [
+      '#markup' => $output,
+    ];
+  }
+}

app/docroot/modules/custom/testblocklast/testblocklast.info.yml

+name: TestBlockLast
+package: Custom
+type: module
+core_version_requirement: ^8.8 || ^9