I share the information I found out.
If you add a fixed-term gold item from TblMerchantSellList and purchase and use the fixed-term item with silver, it will not work.
(Gold items without an expiration date can be used by adding gold items from TblMerchantSellList.)
So, of course, I thought it was possible to use the fixed-term gold item
I researched for 3 days for this problem.
To activate, add a fixed-term item to the SHOP, purchase it, and double-click the purchased fixed-term gold item to use it.
!!!!!!Gold items with expiration dates must be added and used in the SHOP.!!!!!!