I'm finding an one step checkout extension support all functions of shopping cart page with the feature as add coupon code, edit product, remove, update cart. Could you please suggest me some one step checkout extension support this feature?
Thank a lot in advance!
You can refer one step checkout extension from www.magewoo.com on the link: http://www.magewoo.com/one-step-checkout.html. This extension support all function on checkout cart page. Also, you can arrange position of the fields and change the style of one step checkout page to suitable with your theme.
Check this extension out: https://www.magecomp.com/magento-one-step-checkout.html
It fullfils all your requirements.
You can try Fme's One Steo Checkout extension with a text box option to let customers write special note to the merchant while placing order. This is a responsive extension offering all necessory checkout filed in one page.
For more details