Customer created order but not paid

Hi,

If he clicks the back button, then since his cart is empty, he should be redirected to the URL that you entered in the "URL where to redirect when the cart is empty" of the HikaShop configuration.
If you want to allow him to pay the created order, you can activate the "Payment of orders not paid immediately" setting of the HikaShop configuration. Then, on his orders listing, he'll have a "pay" button for each created order.
You can also create a menu item of the type "HikaShop orders listing" via the Joomla menu manager if you want to have a link to the orders listing in your website menu so that he can easily find the orders listing page.