Print image with alt text
Print the image field in the node template like any other field:

{{ content.field_gallery }}

And then use a field twig to loop through multiple field items:

field--field-gallery.html.twig

 &lt;div class="row expanded"&gt;
  {% for item in items %}
     {{ item.content }}
     {{ item.alt }}
    {% endfor %}
  &lt;/div&gt;