How does android check internet availability?

Question

Android

Setting up wifi hotspot. When trying to open any site in the user's browser, it redirects to the login page, after which all connections become available to him.
The problem is that android thinks that the wifi network does not have access to the Internet (exclamation mark next to the wifi icon), and continues to go to the Internet via the cellular network, unless mobile traffic is disabled in the settings.
A similar problem with the iPhone was solved by allowing access to some apple domains that are being checked.
What domains / ip addresses does the android access for a similar check?

Answer 1

As an option - snifat traffic.