This Unreal Engine 5.4 video is about updating the logic for Upgrade and Breakdown Tower Actions.
We start by updating the UI to make it clear that Breakdown is a refund, and then add a function to Refund Coins. Next, we split out the Set Tower Attributes logic into a function for re-use, and build the Upgrade Tower Function which calls it. Lastly, we update the Do Tower Action function to handle the Update and Breakdown Actions.
https://dev.epicgames.com/community/learning/tutorials/l3X6/unreal-engine-37-tower-upgrade-and-breakdown-2-let-s-make-a-tower-defense-game