Pathfinder: Wrath of the Righteous' numerous puzzles span over all the acts and Final Veil is closer to the end of the game, making it somewhat tricky to finish.
Secrets of Creation chain consists of several puzzles with the same two steps - pick up the necessary slabs and then line them up like dominoes. You will not be able to complete this step before Act 5 of Pathfinder: Wrath of the Righteous .
Final Veil slab location and how to reveal it
Final Veil slab location is a little tricky if you're not familiar with this chapter of the game as the location will not appear even if you move next to it on the world map. Instead, you will need to visit Iz first and talk to Hulrun. Ask him about the Sword of Valor and he will reveal Bone Hills on the world map. You can go there whenever you find it fitting, deal with the enemies and loot the slabs.
Final Veil solution
After obtaining the slabs, it's pretty straightforward - leave the area and go straight east to reach Final Veil. You will need to arrange the slabs like in the image shown below.
If you're disoriented by the image, line your in-game compass up with the north and you will look at the puzzle from the same angle. It's easy replicating the slab positions from there.