i create a custom page to display loop of cpt with custom field.

I need to add a numberic pagination and i try with this code but not work.

Functions.php

function pagination_bar() {
    global $wp_query;

    $total_pages = $wp_query->max_num_pages;

    if ($total_pages > 1){
        $current_page = max(1, get_query_var('paged'));

        echo paginate_links(array(
            'base' => get_pagenum_link(1) . '%_%',
            'format' => '/page/%#%',
            'current' => $current_page,
            'total' => $total_pages,
        ));
    }
}

custompage.php

<!--Loop Salmi-->
<?php
$paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1;
$loop = new WP_Query( array( 'post_type' => 'salmi',
        'posts_per_page' => 15,
        'paged'          => $paged )
);
while ( $loop->have_posts() ) : $loop->the_post(); ?>

    <!--Colonne Contenuto -->
    <div class="salmicpt">
        <div class="wpb_column vc_column_container td-pb-span8">
            <div class="titlecpt"><?php the_title(); ?></div>
        </div>
        <div class="wpb_column vc_column_container td-pb-span4">
            <?php if( get_field('audio_salmi') ): ?>
                <a href="<?php the_field('audio_salmi'); ?>" ><img src="mysite.com/wp-content/uploads/cuffia-cpt-e1481533293805.png" alt="Ascolta" title="Ascolta" /></a>
            <?php endif; ?>
            <?php if( get_field('salmi_pdf') ): ?>
                <a href="<?php the_field('salmi_pdf'); ?>" ><img src="mysite.com/wp-content/uploads/freccia-32.png" alt="Scarica il PDf" title="Scarica il PDF" /></a>
            <?php endif; ?>
        </div>
        <div style='clear:both'></div><hr class="style-one" />
    </div>
    <nav class="pagination">
        <?php pagination_bar(); ?>
    </nav>

<?php endwhile; wp_reset_query(); ?> 

Where is wrong?? Thanks