I am trying to add giftcard product to cart but its not working it shows "Please specify a delivery date." error on frontend.
Magento ver. 2.4.1 Commerce
I believe you have some customizations in there. There is no delivery date info on products in the default Magento install. I also tried your flow of adding a giftcard product to cart and no errors occurred on the M2.4.1 with sample data.
My suggestion is to enable a debugger and see what's going on and also check which are the properties set on the product in admin area (attribute set details, etc).