WordPress: Add post types to the 'At a glance' widget

function.php

<?php
add_filter( 'dashboard_glance_items', 'custom_glance_items', 10, 1 );

function custom_glance_items( $items = array() ) {

    $post_types = array( 'post_type_1', 'post_type_2' );
    
    foreach( $post_types as $type ) {

        if( ! post_type_exists( $type ) ) continue;

        $num_posts = wp_count_posts( $type );
        
        if( $num_posts ) {
            
            $published = intval( $num_posts->publish );
            $post_type = get_post_type_object( $type );
            
            $text = _n( '%s ' . $post_type->labels->singular_name, '%s ' . $post_type->labels->name, $published, 'your_textdomain' );
            $text = sprintf( $text, number_format_i18n( $published ) );
            
            if ( current_user_can( $post_type->cap->edit_posts ) ) {
                $items[] = sprintf( '<a class="%1$s-count" href="edit.php?post_type=%1$s">%2$s</a>', $type, $text ) . "\n";
            } else {
                $items[] = sprintf( '<span class="%1$s-count">%2$s</span>', $type, $text ) . "\n";
            }
        }
    }
    
    return $items;
}
?>

style.css

#dashboard_right_now a.post_type-count:before,
#dashboard_right_now span.post_type-count:before {
  content: "\f109";
}