Bringing your ad accounts into your Business Manager account is just a few easy steps.
Start with your ad account – this can either be one that already exists that you own, one that already exists that someone else owns or you can set up a brand new, shiny one. Then, just follow the next 5 steps:
Go to business settings
Click Accounts and then Ad accounts
When shown three options, choose: Add ad account
Enter the ad account ID. Learn where to find the account ID.