{{ page.footer }}

function template_preprocess_region(&$variables) {
  if ($variables['region'] == 'footer') {
    $variables['content'] = 1;
  }
}

/**
 * Implements hook_preprocess_page() for page.html.twig.
 */
 function hook_preprocess_page(array &$variables) {
   $variables['page']['footer'] = [     # Specify the region name
     '#theme_wrappers' => ['region'],
     '#region' => 'footer',             # Specify the region name
     'phantom_block' => [
       '#markup' => ' ',
       '#weight' => "-100",
     ],
   ];
 }