How do i enable auth_basic on nginx for a domain and multiple subdomains with only one password? - linux

Question

I successfully added the auth_basic directive to my server block with the following config:
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=proxy_cache_path_global:10m loader_threshold=300 loader_files=200 max_size=2g inactive=60m use_temp_path=off;
upstream backend {
server localhost:8080;
keepalive 128;
}
server {
listen 443 ssl;
listen [::]:443 ssl;
server_name example.com www.example.com app.example.com;
auth_basic "Administrator’s Area";
auth_basic_user_file /etc/nginx/.htpasswd;
location / {
proxy_pass http://backend;
proxy_cache_methods GET HEAD;
proxy_cache proxy_cache_path_global;
proxy_cache_key $host$request_uri$cookie_user$slice_range;
proxy_cache_bypass $cookie_nocache $arg_nocache$arg_comment;
proxy_cache_min_uses 3;
proxy_cache_valid any 1m;
proxy_cache_revalidate on;
proxy_cache_background_update on;
proxy_cache_lock on;
proxy_cache_lock_age 10s;
proxy_cache_lock_timeout 3s;
proxy_redirect off;
proxy_http_version 1.1;
proxy_read_timeout 300;
proxy_connect_timeout 300;
slice 1m;
add_header X-Cache-Status $upstream_cache_status;
proxy_set_header Host $host;
proxy_set_header Connection "";
proxy_set_header Range $slice_range;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Port $server_port;
}
}
When i visit my website, 2 login prompts appear after each other; one for example.com, and another one for app.example.com.
How do i configure this, so that i only have to type in my credentials once?
I already tried looking for a solution by myself unsuccessfully. Any hints would be appreciated.