add_action('publish_post', function( $ID, $post ) {
    if ($post->post_type == 'post') {
        $webhook_url = 'https://example.com/webhook-endpoint';

        $response = wp_remote_post(
            $webhook_url,
            array(
                'method' => 'POST',
                'body'   => json_encode( $post ),
                'headers' => array('Content-Type' => 'application/json')
            )
        );
    }
}, 10, 2);