D) Power the gateway up. Booting log will be showed in the PuTTY terminal, in the end it will prompt you to input your log in name. Please note it takes 1 or 2 minutes to get the prompt information

It should ask for rhfs login according to instructions mentioned on page “https://wiki.seeedstudio.com/LoRa_LoRaWan_Gateway_Kit/#getting-started” mentioned as step 1: part d)