How to find Image URI in Kint via .entity in the node tree
Every image in Drupal 8 is a file entity.

You can try in template_preprocess_node():

$image_file_id = $variables['node']-&gt;field_image[0]-&gt;target_id;
$image_file = \Drupal\file\Entity\File::load($image_file_id);
$uri = $image_file-&gt;uri-&gt;value;