Wow the killer have great model and animation!
I figured out that you need to understand if the NPCs are lying, but I haven't felt like I have the tools to know that. I saw that you talked about how it was implemented in the comments and asked for some ideas.
Fitst, I don't think you specified the order of the password. I gueesed that the order is me, and than according to the order in the UI, and it seem to work when everybody told the truth - but it's better to specify it, or just allow to input the numbers in any order
You did specify the numbers are unique, but I someow missed that. This can be emphasized by bold/red/repeat etc
Next, thematically, it wasn't clear who will die if we guesed wrong/right, and who guessed wrong/right. Think about a case where I have 1 other person - it's a classical prisoner delimma - if we both lie, we both die, but it's not clear what happens if we both tell the truth.
One way this can work is if each character have specific rules - always lies, always tell the truth etc - and if after each night, the killer tells you who got it right and who got it wrong, and kills a random person who got it wrong. This way you have some information to work with.
Anyways, great work!