add pagination to the category

category.php

<?php numeric_posts_nav(); ?>

functions.php

// numeric posts navigation

function numeric_posts_nav() {

    if( is_singular() )
        return;

    global $wp_query;

    /** Stop execution if there's only 1 page */
    if( $wp_query->max_num_pages <= 1 )
        return;

    $paged = get_query_var( 'paged' ) ? absint( get_query_var( 'paged' ) ) : 1;
    $max   = intval( $wp_query->max_num_pages );

    /** Add current page to the array */
    if ( $paged >= 1 )
        $links[] = $paged;

    /** Add the pages around the current page to the array */
    if ( $paged >= 3 ) {
        $links[] = $paged - 1;
        $links[] = $paged - 2;
    }

    if ( ( $paged + 2 ) <= $max ) {
        $links[] = $paged + 2;
        $links[] = $paged + 1;
    }

    echo '<div class="pagination-navigation col-md-12"><ul class="d-flex justify-content-center">' . "\n";

    /** Previous Post Link */
    if ( get_previous_posts_link() )
        printf( '<li>%s</li>' . "\n", get_previous_posts_link() );

    /** Link to first page, plus ellipses if necessary */
    if ( ! in_array( 1, $links ) ) {
        $class = 1 == $paged ? ' class="active"' : '';

        printf( '<li%s><a href="%s">%s</a></li>' . "\n", $class, esc_url( get_pagenum_link( 1 ) ), '1' );

        if ( ! in_array( 2, $links ) )
            echo '<li>…</li>';
    }

    /** Link to current page, plus 2 pages in either direction if necessary */
    sort( $links );
    foreach ( (array) $links as $link ) {
        $class = $paged == $link ? ' class="active"' : '';
        printf( '<li%s><a href="%s">%s</a></li>' . "\n", $class, esc_url( get_pagenum_link( $link ) ), $link );
    }

    /** Link to last page, plus ellipses if necessary */
    if ( ! in_array( $max, $links ) ) {
        if ( ! in_array( $max - 1, $links ) )
            echo '<li>…</li>' . "\n";

        $class = $paged == $max ? ' class="active"' : '';
        printf( '<li%s><a href="%s">%s</a></li>' . "\n", $class, esc_url( get_pagenum_link( $max ) ), $max );
    }

    /** Next Post Link */
    if ( get_next_posts_link() )
        printf( '<li>%s</li>' . "\n", get_next_posts_link() );

    echo '</ul></div>' . "\n";

}


// numbered pagination
function pagination($pages = '', $range = 4)
{
     $showitems = ($range * 2)+1;

     global $paged;
     if(empty($paged)) $paged = 1;

     if($pages == '')
     {
         global $wp_query;
         $pages = $wp_query->max_num_pages;
         if(!$pages)
         {
             $pages = 1;
         }
     }

     if(1 != $pages)
     {
         echo "<div class=\"pagination\"><span>Page ".$paged." of ".$pages."</span>";
         if($paged > 2 && $paged > $range+1 && $showitems < $pages) echo "<a href='".get_pagenum_link(1)."'>&laquo; First</a>";
         if($paged > 1 && $showitems < $pages) echo "<a href='".get_pagenum_link($paged - 1)."'>&lsaquo; Previous</a>";

         for ($i=1; $i <= $pages; $i++)
         {
             if (1 != $pages &&( !($i >= $paged+$range+1 || $i <= $paged-$range-1) || $pages <= $showitems ))
             {
                 echo ($paged == $i)? "<span class=\"current\">".$i."</span>":"<a href='".get_pagenum_link($i)."' class=\"inactive\">".$i."</a>";
             }
         }

         if ($paged < $pages && $showitems < $pages) echo "<a href=\"".get_pagenum_link($paged + 1)."\">Next &rsaquo;</a>";
         if ($paged < $pages-1 &&  $paged+$range-1 < $pages && $showitems < $pages) echo "<a href='".get_pagenum_link($pages)."'>Last &raquo;</a>";
         echo "</div>\n";
     }
}