Is similar block generation possible in Drupal 8?

Question

Drupal

During authorization for the user, blocks with links to his tasks should be generated and displayed. We get information about tasks from a third-party source. Based on blog.dev030.com/posts/dynamically-define-blocks-dr... , I got Drupal to generate blocks, but now how to fill them with links and output them automatically every time only to the right users.