{% for key, item in node.field_slides %}
{% if node.field_slides[key].entity %}
<figure class="swiper-slide">
    <img class="swiper-image" src="{{ file_url(node.field_slides[key].entity.uri.value) }}" alt="{{ node.field_slides[key].alt  }}" />

    {% if node.field_slides[key].title %}
    <figcaption class="swiper-caption">
        <div class="swiper-user-content user-content">
            {{ node.field_slides[key].title|striptags("<a>,<h1>,<h2>,<h3>,<h4>,<h5>,<h6>,<ol>,<p>,<table>,<ul>")|raw }}
        </div><!--/.swiper-user-content.user-content-->
    </figcaption><!--/.swiper-caption-->
    {% endif %}
</figure><!--/.swiper-slide-->
{% endif %}
{% endfor %}

{{ file_url(node.field_slides[key].entity.uri.value) }}