In order to make purchases, you will need an active Google Play account for Android Devices or an active Apple ID account for iPhones. You will either need to redeem a gift card with monetary value to these accounts or connect them to a credit card.

Once your account has been set up, simply tap the "Shop" button located at the bottom of your game screen. This will bring up different types of sales; coins which can be purchased with your Apple ID or Google Play account, and Royale boosters which can be purchased with coins.