get_post_meta not working

get_post_meta not working for fetch single post shortcode.
my code is
function product_shortcode_fn( $atts ) {

$atts = shortcode_atts( array(
‘posts_per_page’ => ‘-1’,
‘term’ => ”
), $atts, ‘myprefix_custom_grid’ );

extract( $atts );
$output = ”;
$query_args = array(
‘post_type’ => ‘asp-products’, // Change this to the type of post you want to show
‘posts_per_page’ => $posts_per_page,
);
if ( $term ) {

$query_args[‘tax_query’] = array(
array(
‘taxonomy’ => ‘category’,
‘field’ => ‘ID’,
‘terms’ => $term,
),
);
}
$custom_query = new WP_Query( $query_args );
if ( $custom_query->have_posts() ) {
$output .= ‘<div>’;
while ( $custom_query->have_posts() ) {
$custom_query->the_post();
$output .= ‘<div class=”col-md-4″ style=”padding-bottom:40px;”>’;
$output .= get_the_title();
$output .= get_post_meta(get_the_ID(),’_asp_product_shortcode’,true);
$output .= ‘</div>’;
}
$output .= ‘</div>’;
wp_reset_postdata();
}
return $output;
}
add_shortcode( ‘products’, ‘product_shortcode_fn’ );

please help me.

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