I don’t really know how to make a “keyring” ect.
Create a new variable, give it a desired name (here, “keyring” - makes sense to me but it makes less sense if you’re making a sci-fi game) and make the container type a set:
Sets offer some truly efficient look-up algorithms and other unique operations. Think of a neatly catalogued container where you need to spend no time finding stuff.
I suggested a Set here as it can contain unique items only. Were you to pick up 10 identical keys, you’d still have 1 key only, without worrying about anything dupes. A set will have no duplicates.