I'm using NextAuth in my web app and I've implemented authentication using the Google OAuth 2.0 service as one provider.
This service is located at the console.cloud.google.com page of Google Cloud, in the section of APIs & Services > Credentials > OAuth 2.0 Client IDs
Since I only used Firebase, I have it not clear if this service charges after some period or if the service exceeds some parameters, and if it does, how costs are measured.
I tried the Google Cost Calculator, but there is a lot of services I was not able find it right.
If you are using google identity plat form you can check price at here.
It says it is free until MAU reaches 49,999.