We have posted simple Bootstrap Pagination function snippets that will easily apply Bootstrap Class to the every pagination element.

function page_navigation($before = '', $after = '') {
    global $wpdb, $wp_query;
    $request = $wp_query->request;
    $posts_per_page = intval(get_query_var('posts_per_page'));
    $paged = intval(get_query_var('paged'));
    $numposts = $wp_query->found_posts;
    $max_page = $wp_query->max_num_pages;
    if ( $numposts <= $posts_per_page ) { return; }
    if(empty($paged) || $paged == 0) {
        $paged = 1;
    }

Just follow the below steps for it: