Load node entity from external script with image URI
you can try:

$image_uri  = $node-&gt;field_image_field-&gt;entity-&gt;getFileUri();

echo $image_uri;

$image_url= file_create_url($image_uri);

echo $image_url;


in the variable "$ image_uri" contains the uri of the image.

in the variable "$ image_url" contains the complete url of the image.

Note: please, change field_image_field for your machine name field