Activate a Peace Shield and other boosts through the Boost Page, available in your Base and World Map view.
You can use Boost Items you own already, or purchase them for Gold. You can also use boost items from your inventory if you already own them by navigating to the Bag menu, via the bottom navigation, bar and selecting ‘Combat’.
Once your Peace Shield is active, the Base Boost popup will display a timer counting down, and you'll also be able to see a shortened countdown under the Boost Icon inside your base.