Govi creation ritual. You first need to know where to do this ritual. This happens after you get away from the tropical island.
You know what soul you are trying to get into the urn Use the clay pot on the soul. Then you can insert the ingredients into it.
Ingredients:
Unlike normal walkthroughs, in Nice Game Hints you can select just the puzzle you want hints for. Here are listed the puzzles for "Urn a soul" in Voodoo Detective. The guide you choose only contains information about that puzzle, reducing possible spoilers for other puzzles.