Add buttons to order confirmation in payment

Hello! I want to add 2 buttons - view invoice and print invoice in order confirmation on payment.
Could u please tell me how to do it on the best way?

And one more question for asap - how to overwrite CheckoutCompleted - I also want to add 2 more buttons there.

art_MOO wrote:

You can implement a plugin for override the following route ==>

   routes.MapLocalizedRoute("CheckoutCompleted",
                            "checkout/completed/{orderId}",
                            new { controller = "Checkout", action = "Completed", orderId = UrlParameter.Optional },
                            new { orderId = @"\d+" },
                            new[] { "Nop.Web.Controllers" });

  

Plugin code will be like bellow ==>

routes.MapLocalizedRoute("yourPluginCheckoutCompleted",
                            "checkout/completed/{orderId}",
                            new { controller = "yourCheckout", action = "Completed", orderId = UrlParameter.Optional },
                            new { orderId = @"\d+" },
                            new[] { "Nop.YourPlugin.Controllers" });

Note: url will same.