The Flipper Zero is broadcasting a WiFi network with the same SSID as the real train WiFi. My device connects to it instead of the real network. My "evil twin" network shows a login page asking for Google email and password. Anything entered is saved on the Flipper and shows on the screen.

A Pineapple can run much more advanced attack but it's also a dedicated router. A working evil portal attack can run off a simple Flipper with the WiFi board.