Gift code does not apply discount

Hi there, I’m using the latest version of Woocommerce and Gift card plugin 2.0. When I enter the gift code at checkout, there is an error that says “enter coupon code” and no discount is applied to the order.

I can create the gift card product, create gift card and coupon, send email with the gift code with no problems. Just that the code doesn’t work at checkout.

https://ww.wp.xz.cn/plugins/gift-cards-for-woocommerce/