Creating the payment method of point payment

-- url of the page with the problem -- : www.realflightshop,com
-- HikaShop version -- : 2.6.3
-- Joomla version -- : 3.6.1
-- Error-message(debug-mod must be tuned on) -- : Message
The Virtual coupon mode cannot be used for partial payment with points. Either deactivate the Virtual coupon mode or the partial payment. Otherwise, you won't see any payment with points on the checkout

Hi

I have read the tutorial of user point setting.
When I create a payment for HikaShop User Points payment plugin, when I save it, it appear the message something like that,
"Message
The Virtual coupon mode cannot be used for partial payment with points. Either deactivate the Virtual coupon mode or the partial payment. Otherwise, you won't see any payment with points on the checkout"

What dose this mean and how to make the point payment available when checkout.

Thanks!