Firstly you need an account at chartboost to start monetize your game with chartboost ads. Please visit following link to login or to setup a new account.
Click on Start Making Money (You can skip that if you already had setup an account in chartboost). After that chartboost searches the apps stores for your company name. If there are no results you can either adjust your company name or select that you have no apps published yet.
Add your App(s)
If chartboost finds your published apps, it will look like that. Now you can select those apps you want to monetize with chardboost.
Click “Add selected” to continue. Now you need to select the game orientation for each added game.
Create your Campaign(s)
After that you can select the ad types you want to use. Confirm your selection with “Create Campaign”
If all went fine, you will see your ID’s for each app.