How to get current url in contact form 7

See this example on how to create and parse the shortcode in the contact form 7 to use it add [current_url]

add_action( 'wpcf7_init', 'wpcf7_add_form_tag_current_url' );
function wpcf7_add_form_tag_current_url() {
    // Add shortcode for the form [current_url]
    wpcf7_add_form_tag( 'current_url',
        'wpcf7_current_url_form_tag_handler',
        array(
            'name-attr' => true
        )
    );
}

// Parse the shortcode in the frontend
function wpcf7_current_url_form_tag_handler( $tag ) {
    global $wp;
    $url = home_url( $wp->request );
    return '<input type="hidden" name="'.$tag['name'].'" value="'.$url.'" />';
}

Also if its all about to get the URL in the email you dont need all of this. there is a special tag for the email [_url] CF7 Special mail tags