The way I have set it up is to activate a custom event whenever the key has been picked up to set a boolean to be true (Key Picked). You could create a custom event per key and have each of them set a different boolean to being true. Then add 3 separate branches (where I have only one) and attach each of the booleans to them. This way the door will only unlock if all 3 have been picked up. I’ve also included a screenshot of how I got the key to activate the custom event.
