key update

Hi, I have a notification on all sites that use your plugin saying

Premium Key that were bought before 24th Sep, 2018 will no longer work in Use Any Font 5.0. So please get your replacement key here. You do not need to pay again. Use your old Premium Key as Discount Coupon and it will apply 100% discount.

When I use my current key as the discount code it’s not accepting it for any of my websites. Can you help??

Kelly