What is the name of the user authorization page after connecting to the public network?

Question

Computer networks

In the subway or cafe or anywhere else, when connected to a public network, a window appears with a field for entering a phone number or otherwise authenticating a user in the current domain . What is this modern technology called , where to dig, in general, I can’t even formulate a question to Google. I thought that some special mb DHCPINFORM comes and the network manager processes it by showing this webview, but it seems that it doesn’t.

Answer 1

Captive Portal

Answer 2

A hotspot with authorization on the web interface is called a Captive Portal.

Answer 3

hotspot