Maybe stupid question. How to upgrade set items? I play ladder, use receipt for unique items and nothing. Is it work or will start work after ladder?

i don't think a unique item is the same as a set item.

https://www.wowhead.com/diablo-2/news/upgrading-set-items-in-horadric-cube-in-patch-2-4-ptr-in-diablo-ii-resurrected-325779

Upgrade Normal Set Weapon to Exceptional
Same iLvl & properties
Runes, jewels & gems retained 1x Normal Set Weapon+ 1 Ral Rune+ 1 Sol Rune+ 1x Perfect Emerald

Upgrade Exceptional Set Weapon to Elite
Same iLvl & properties
Runes, jewels & gems retained 1x Exceptional Set Weapon+ 1 Lum Rune+ 1 Pul Rune+ 1x Perfect Emerald

Upgrade Normal Set Armor to Exceptional
Same iLvl & properties
Runes, jewels & gems retained 1x Normal Set Armor+ 1 Tal Rune+ 1 Shael Rune+ 1x Perfect Diamond

Upgrade Exceptional Set Armor to Elite
Same iLvl & properties
Runes, jewels & gems retained 1x Exceptional Set Armor+ 1 Ko Rune+ 1 Lem Rune+ 1x Perfect Diamond

I use this receipt amd don't work.

could you give an exact example of what you are trying to do? which item etc?

You are trying to up an elite item most likely