Go to admanager.google.com and sign in to your account. Set up the network setting, including your time zone and currency. After that, you need to create your inventory structure and add Google Publisher Tags to your pages. Make sure you request app ads through Google Mobile Ads SDK and video ads through Google IMA SDK. Once this is done, you can start trafficking ads to your inventory by creating orders and line items, followed by uploading creatives, and finally approving orders.
How do I use Google Ad Manager?
Naomi Rabbie, July 15, 2021