Image isn’t displaying in template

I tried to follow the instructions in order to display the second featured image but the page isn’t displaying the second image. First, I added this following code to functions.php after installing the plugin.

add_filter( 'kdmfi_featured_images', function( $featured_images ) {
$args = array(
'id' => 'featured-image-2',
'desc' => 'Your description here.',
'label_name' => 'Featured Image 2',
'label_set' => 'Set featured image 2',
'label_remove' => 'Remove featured image 2',
'label_use' => 'Set featured image 2',
'post_type' => array( 'galeria' ),
);

$featured_images[] = $args;

return $featured_images;
});

Then, after adding a photo to the second featured image in the post, I tried to add the following code to the single.php.

<div class="single_image">
<?php
	if(has_post_thumbnail()) {                    
	    $image_src = wp_get_attachment_image_src( get_post_thumbnail_id(),'full' );
	     echo '<img src="' . $image_src[0]  . '" width="100%"  />';
	} 
?>

<?php 
if( kdmfi_has_featured_image() ) {
	$secondimage_src =   kdmfi_get_featured_image_src( 'featured-image-2', 'full' );
	     echo '<img src="' . $secondimage_src[0]  . '" width="100%"  />';
}
?>
</div>

As you can see, the first part display the first featured image. However the last part wouldn’t display the second featured image. Please help!