How to Monetize your App with AdMob? [Instructions with Pictures]
Step 1. Log in to your AdMob account at https://apps.admob.com.
Step 2. Click Apps in the sidebar
Step 3. click on add your first app
Step 4. Select the platfrom Android or iOS and tick mark the option yes or no if the app supported app store
Step 5. Click on continue button
Step 6. Enter app name 
Step 7. Click on Add app button 
Step 8. When app is successfully added then click on create ad unit 
Step 9. Select Banner
Step 10. Enter Ad unit name 
Step 11 : Click on create ad unit button
Step 12. You should now see your apps 'Ad unit ID' in a format such as 'ca-app-pub-XXXXXXXXXXXXXXXX/XXXXXXXXXX' where 'X' represents integers. Copy and paste that value into the 'AdMob Ad Unit ID' field in your App , after that click on create another ad unit.
Step 13. Select Interstitial
Step 14. Enter Ad unit name and click on create ad unit button
Step 15.You should now see your apps 'Ad unit ID' in a format such as 'ca-app-pub-XXXXXXXXXXXXXXXX/XXXXXXXXXX' where 'X' represents integers. Copy and paste that value into the 'AdMob Ad Unit ID' field in your App. And click on Done
Step 16. Click on Settings
Step 17. Click on Account Information
Step 18. Here is your Publisher ID.Copy and paste that value into the field in your App and Click Apps in the sidebar
Step 19. Click on View all App
Step 20. Click on Set up app-ads.txt
Step 21. In the popup, you will find your Google Snippet Code. Copy this code to your clipboard, then click on GOT IT.
Step 22. Under the Apps tab, select your App.
Step 23. Click App settings in the left side Apps menu.
Step 24. In the App info section, you will find your App ID. Copy this App ID to your clipboard.
Step 25. Paste the copied Admob Ad unit ID: Banner Ad, Interstitial Ad, Publisher ID, Privacy policy URL, Google Snippet Code, and Application ID (App ID) in their respective fields on creator software.
Note : In the Privacy Policy Url field, you need to enter Privacy Policy Url that you have created for your app.