As part of the casting of this spell, you place a copper piece under your tongue. This spell makes up to six willing creatures you can see within range invisible to undead for the duration. Anything a target is wearing or carrying is invisible as long as it is on the target's person. The spell ends for all targets if one target attacks or casts a spell.
Using a Higher-Level Spell Slot. When you cast this spell using a 3rd-level spell slot, it lasts for 1 hour without requiring your concentration. When you cast this spell using a spell slot of 4th level or higher, the duration increases by 1 hour for each slot level above 3rd.