I use Google play service (ads) in my old app and after updating library I've got an issue
Autoclick (dwell timing)
File google-services.json is missing. The Google Services Plugin cannot function without it.
At this link https://developers.google.com/mobile/add I might generate nessesary json file but I have to selected google play service: sign-in, analytics, cloud messaging.
What should I choose, because there isn't 'Ads' standalone?
I think the reason you're not seeing Ads in the link you've provided is because AdMob is now being handled by Firebase. They've made the steps simpler as stated in the docs:
The best way to use AdMob is with Firebase. Firebase is a mobile platform that helps you quickly develop high-quality apps, grow an engaged user base, and earn more money. Since AdMob is now a part of Firebase, we've made it simpler to use AdMob along with other Firebase services such as Analytics.
Check the Integrate Firebase and the Mobile Ads SDK for the implementation part. Kindly check their guide for more info. Hope this post helps.