We will add a very simple in-app purchase in the game so that, if the player wishes, they can pay the minimum amount to remove the ad at the bottom of the screen.
For this, we need a paid developer account to add in-app purchases. The annual fee is 99 USD, and with this you can publish on the iOS / macOS App Store. Once you have paid Apple the amount, signed the contract, and updated your tax and banking information, go to itunesconnect.apple.com and My Apps:
Create a new app by clicking on the + sign in the upper-left corner of the page:
Select the Platform, Name, Primary Language, Bundle ID, and SKU.
If you don't have a