You might try the Amazon forum .com which has staff answering questions. The browser has always launched for me to enter the information.

Below is from the Amazon forum. My Firestick has the browser installed. Sounds like the browser isn’t installed by default.


Fire TV Stick does not have a dedicated web browser, but they do have a hidden app (CaptivePortalLauncher) that will open a web page to access a captive portal. This app will open a browser window only during Wi-Fi sign in.

1. From the Home screen, select Settings> System > Wi-Fi.
2. Under Available Networks, select the public Wi-Fi network. For networks that require a web page to log in, a browser window will pop up after several seconds.
3. Follow the on-screen instructions to use your Amazon remote to select text fields or enter cursor mode to select a button. An on-screen keyboard will open for text fields.
4. Enter in the required information. This could be a pre shared password, room number, or just a button to accept conditions for using the network. Contact the network owner for more information
5. After your device connects to the network, the browser window closes automatically.