What service to use for targeting banners inside the personal account of the site?

Question

Marketing

The task is to target your own advertising banners inside the site's personal account to certain user groups (for example, users who indicated their city of residence Moscow - one banner, and those who indicated St. Petersburg - another).
I looked and played around with Google Ad Manager (Former DFP) - it seems to be suitable in terms of functionality, but sooooo difficult to set up and manage. There are some services similar in functionality that can solve the task, but with a simpler interface and without such a wide range of add-ons. options? Or would it be easier and cheaper to write your own solution?