Select posts from Category

In my opinion, you should avoid using common words like “images”. It can be confusing for the system.

A previous post on SO nailed the use of images using Category ID. Here’s your edited code:

<?php 
$your_category_ID = '1'      

$query = new WP_Query( 'cat=$your_category_ID' );

if ( $query->have_posts() ) {

    while ( $query->have_posts() ) : $query->the_post(); 

        $src = wp_get_attachment_image_src( get_post_thumbnail_id($query->ID), array( 5600,1000 ), false, '' ); ?>
        <a href="https://wordpress.stackexchange.com/questions/169970/<?php echo $src[0]; ?>" data-lightbox="image-77" data-title="<?php query->the_title() ?>">
        <div class="item">
            <div class="lazyOwl" style="background:url(<?php echo $src[0]; ?>) no-repeat center center;background-size:cover;height:300px;" alt=""></div>
            </div>
        </a>

    endwhile; 

    /* Restore postdata */
    wp_reset_postdata();    

}
?>