Hello
I have worked with Unity services before. At the moment I have my app that gets the services information for me. I use that with the googleplay store to make educated decisions and totally recommend it. I know how to incorporate ads as well as incorporate buying in game items and subscriptions and deals for apple and google play.
Should you be needing more than what is supplied here let me know, I am very proficient in C#. Also feel free to start discussing what would be needed of me.
I would recommend using rewarded video ads. There is a lot of research showing that people are more likely to enjoy choosing themselves to be exposed to adverts, that brings you revenue, if it gives them a reward rather than just having ads.
Do have the app.