Authorization header in Nginx for proxying to basic auth backend does't work

https://joshuarogers.net/articles/2015-06/passing-static-credentials-upstream-through-nginx/ http://shairosenfeld.blogspot.jp/2011/03/authorization-header-in-nginx-for.html I googled around and found these two tutorials about using Nginx for proxying to basic auth. I configured Nginx server in my local host, and restarted. But it doesn't seem to work. I could access the host(http://10.211.55.12:5601 and http://10.211.55.12:80 redirected to the same page in previous) without auth. The service in "http://10.211.55.12:5601" is Kibana, I want to secure it with auth. ``` # Default server configuration # server { listen 80 default_server; listen [::]:80 default_server; server_name _; location / { proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass http://10.211.55.12:5601; proxy_set_header Authorization "Basic a2luZzppc25ha2Vk"; } } ```