WiFi does not ask for password

I'm now in a coffee shop, which I've never been before. A moment ago, I had problem with connecting with the WiFi here using my MacBook Air Mid 2013 (Mac OS Sierra) but it was ok using my iPhone.

I could see the WiFi name (Amazon BKK 63) in the settings (no padlock symbol though) but it didn't prompt me for password when i clicked on it. It just showed that i'm connected. I then opened Network settings from the System Preferences and saw that "WiFi is connected to Amazon BKK 63 and has the IP address 10.10.10.238", but there was no internet connection.

This is because the WiFi network was not encrypted. Normally, the encrypted networks show the password input dialog box when you choose on the WiFi network name but the unencrypted networks don't.

I tried to access Google from a browser but it just said no internet connection. After that, i opened Terminal and pinged the IP address 10.10.10.238, and i got replies back so the IP was correct and could be reached. I wondered what would happen if i accessed it from browser? I then accidentally typed a wrong IP address, 10.10.10.239, in the browser's address bar and it redirected me to the WiFi's login page. I typed the password and then I got the connection. And when i typed the IP address 10.10.10.238, it said that "The site can't be reached". I have no idea what those IP addresses are.

I've got more tips on how to solve this problem from this web site, and i think i will try one of his methods if i get this problem again in the future. He said we should try to load router's default page by entering these IP addresses: 127.1.1.1, 1.1.1.1, http://localhost, in the browser's address bar. If it still doesn't work, try the IP address shown in the Network setting (10.10.10.238 in my case above) or the router's IP address (e.g. 10.10.10.1) by go to Network settings -> Advanced -> TCP/IP. You can also try to open the company's website.