Get the category name with the link

Hi there guys, I am using Flexible Posts Widget, but i can not find related information on their support page. If anyone can help me. Forgive my ignorance but i am trying to add get_the_category
to this piece of code, and i have no idea what do i miss here.

/ Block direct requests
if ( !defined('ABSPATH') )
	die('-1');

echo $before_widget;

if ( !empty($title) )
	echo $before_title . $title . $after_title;

if( $flexible_posts->have_posts() ):
?>
	<ul class="featured-posts row list-inline">
	<?php while( $flexible_posts->have_posts() ) : $flexible_posts->the_post(); global $post; ?>
		<li id="post-<?php the_ID(); ?>" <?php post_class('col-md-4'); ?>>
			<a href="<?php echo the_permalink(); ?>">
				<?php
					if( $thumbnail == true ) {
						// If the post has a feature image, show it
						if( has_post_thumbnail() ) {
							the_post_thumbnail( $thumbsize );
						// Else if the post has a mime type that starts with "image/" then show the image directly.
						} elseif( 'image/' == substr( $post->post_mime_type, 0, 6 ) ) {
							echo wp_get_attachment_image( $post->ID, $thumbsize );
						}
					}
				?>
				<div class="title-block"><h4 class="title-for-widget"><?php the_title(); ?></h4></div>
			</a>
		</li>
	<?php endwhile; ?>
	</ul><!-- .dpe-flexible-posts -->
<?php else: // We have no posts ?>
	<div class="dpe-flexible-posts no-posts">
		<p><?php _e( 'No post found', 'flexible-posts-widget' ); ?></p>
	</div>
<?php
endif; // End have_posts()

echo $after_widget;

Thank you in advance