Okay
So what kind of items do they have to be

Ex.
I have two "magical fine alloy swords"
I put them in and it wont go
Is it cause the "fine" part
Or do the stats on them have to be the same
Like one have +3 dexterity nad another +1% damage return
Will it not work?

Transmutation Box Recipes

All equipment must be magical or higher. You can only transmute weapons, armor, or charms.

Both pieces of equipment must be the same Material Tier.

Items Used Result
Two Weapons of the same Type Rerolled Weapon
Two Armors of the same Type Rerolled Armor
Two Charms of the same Type Rerolled Charm
Armor + Ice Charm Armor with Strength or Mind Numb
Armor + Fire Charm Armor with Intelligence or Armor Pierce
Armor + Lightning Charm Armor with Dexterity or Damage Return
Armor + Wind Charm Armor with Dexterity or Critical Flux
Armor + Earth Charm Armor with Vitality or Block
Armor + Wild Heal Charm Armor with Mana Regen or Luck
Armor + Heal Charm Armor with Mana Regen or Physical Damage Reduction %
Armor + Focused Heal Armor with Life Regen or Magical Damage Reduction %

it will work if they have same level and weapon is same type ( i mean sword with sword , axe with axe and so on )
the result is random and it doesnt matter what stats have the items used for transmute

Thanks this helps
So the two swords in the example wont work?

Magical fine alloy sword
Level Req: 20
Damage: 11 to 117

+1% Damage Return

and

Magical fine alloy sword
Level Req: 20
Damage: 11 to 117

+3 Dexterity

They wont transmute

Nevermind it was glitching
Thanks for your help

it should work np