I am using magento 2.2.7 , i would like to add reorder link in failure page. Please suggest me.
When any payment gets failed then Magento clears the items from cart automatically, so you can better stop the cart items disappearing and add a cart link button only at failure page,
Or you can just redirect to cart page without clearing the cart data with an error of failed payment.
take reference from here :
Hope it helps !