Mine is in Settings, Accounts, Google, Ads. But mine is an older version of Android. I have opted out from interest based ads, but have not recently looked at the "ads settings" bit. There's a lot of stuff to "manage" here - buried deep in the phone!!
As I seldom log in to google - I do not have to to use my phone, I give them as little data as poss.
It is in here somewhere that their evil location tracker tells them exactly where you've been. Apple do the same if you let them.