How to add new tab on woocommerce account page

function npn_id_add_checkout_endpoint() {
    add_rewrite_endpoint( 'checkout', EP_ROOT | EP_PAGES );
}
  
add_action( 'init', 'npn_id_add_checkout_endpoint' );
  
function npn_id_add_checkout_query_vars( $vars ) {
    $vars[] = 'checkout';
    return $vars;
}
  
add_filter( 'query_vars', 'npn_id_add_checkout_query_vars', 0 );

function npn_id_add_checkout_link_my_account( $items ) {
    $items['checkout'] = 'Checkout';
    return $items;
}
  
add_filter( 'woocommerce_account_menu_items', 'npn_id_add_checkout_link_my_account' );
  
function npn_id_add_checkout_content() {
   echo '<h3>This is content</h3>';
}
  
add_action( 'woocommerce_account_premium-support_endpoint', 'npn_id_add_checkout_content' );

function npn_id_add_upgrade_link_my_account( $items ) {
	$upgrade_menu_items = array(
		'upgrade' => esc_html__('Upgrade Package', 'npn-id'),
	);

    return array_slice($items, 0, 5, true) + $upgrade_menu_items + array_slice($items, 1, count($items), true);
}
   
add_filter( 'woocommerce_account_menu_items', 'npn_id_add_upgrade_link_my_account' );