A 3rd and final update is being worked on for Anne
The ending largely doesn't matter as long as it's one of the 3 core endings (not soulless or artifact) and that you gave her your soul then reload the save if Unknown appears in the cahtedral you find the original Anne's soul and/or after the game end sequence then ya know it is working, from there just hit new game and unknown will do her thing.
If the Soulless route is started you'll see it at the start as Unknown will ambush the person trying to knock on the front door.
https://mega.nz/file/KdkiiSBT#_rjQUv6QP3uYBddeK6XW4dumDoviQwIqGKBZiZAE2j8 here is a link to a guide, i dont know how much more ways I can try make it clear, encounter unknown, go through the sequence until she asks for your soui, give it to her, re-open the game and load the save file for the fun you was in when you triggered her, complete an ending and you should see Unknown in the post credits. If she appears then it's time to make a new game and watch the fun unfold.
I've already played the game 3 times and nothing came out. I collected Anna's souls and did not collect them. Maybe I can't find her somewhere? I collected it by a tree, in a house with a peony, and where to get the key from the basement. I didn't find any more of Anna's souls. You can send me a screenshot of where the right soul is, please, for the unknown one, so that we can make these scenes already.