Set Rabbit-Hole values for a node programmatically

This is correct answer.

8.x-1.x version:

$entity->set('rh_action', 'page_redirect');
$entity->set('rh_redirect', 'https://savelife.in.ua/en/');
$entity->set('rh_redirect_response', 307);
$entity->set('rh_redirect_fallback_action', 'access_denied')

2.0.x version:

$entity->set('rabbit_hole__settings', [
  'action' => 'page_redirect',
  'settings' => [
    'redirect' => 'https://savelife.in.ua/en/',
    'redirect_code' => 307,
    'redirect_fallback_action' => 'access_denied',
  ],
]);