As a phantom rogue when someone dies you can make them into a soul trinket as a reaction, to use later for a few abilities.
At 9th level, when a life ends in your presence, you're able to snatch a token from the departing soul, a sliver of its life essence that takes physical form: as a reaction when a creature you can see dies within 30 feet of you, you can open your free hand and cause a Tiny trinket to appear there, a soul trinket. The DM determines the trinket's form or has you roll on the Trinkets table in the Player's Handbook to generate it.
Say a player character dies and the Phantom Rogue uses their reaction to make a soul trinket, as they might want to talk to the player character later.
As an action, you can destroy one of your soul trinkets, no matter where it's located. When you do so, you can ask the spirit associated with the trinket one question. The spirit appears to you and answers in a language it knew in life. It's under no obligation to be truthful, and it answers as concisely as possible, eager to be free. The spirit knows only what it knew in life, as determined by the DM.
You have to decide to do it immediately with your reaction, or before your next turn at least depending on what you dm rules.
Now that you have a soul trinket of them does this mean they can't be resurrected?
I would argue yes as most resurrection spells require a "willing soul" and as quoted above the soul is eager to be free which implies to me that it couldn't leave of its own volition before.
But this does then leave us in a weird place with revivify as that doesn't require a "willing soul".