Follow the instructions below to add Admob Ads to your app:
1. Create an adWords account
To login to AdMob you need a Google Adwords account. Create one first at https://adwords.google.com
2. Login to AdMob
Go to: https://www.google.com/ads/admob/ and create your account after choosing your Adwords account.
Click on “Apps”, then Click “ADD APP“:
Next, if you published your app, click on “YES“, you will have to search for your app on the stores. If “NO“, enter an “App name” and select the platform on which you want to publish your app:
Note the Ad Unit ID:
3. Add your Ad Unit ID into your App Manager
A) Log into your App Manager and select your app.
B) Click Publication from the left-hand-side of the screen (or the middle of the screen).
C) Scroll down to theMonetize my app using AdMob? section and enter the Ad Unit ID you just created: