Can't enchance ring of crescent guardin using burning moonlight black stone

As below guide, I can enchance ring of crescent guardin from 0 to PRI by 5 burning moonlight black stone but I can't choose it as materials.
https://grumpygreen.cricket/pen-accessory/

 

Hello and Welcome to the GamezBD Forum community, I have just looked at the link you supplied, and it seems as if it is a part of an Event: "BDO Pen Accessory Event"

So, while I am not sure, it may be because GamezBD hasn't applied the event in question, or that the lastest update doesn't contain said Event.

Just in case this turns out to be a bug, I suggest you create a Bug Report about this, just remember to include proper proof, such as screenshots or video, which you can make with the inbuilt Windows Video Recorder, WinKey+G.

 

I see, Thank you