#first edit beets.yml and enable the reverse proxy settings, under "web" add "reverse_proxy: true" and restart the beets container

location /beets {
    # enable the next two lines for http auth
    #auth_basic "Restricted";
    #auth_basic_user_file /config/nginx/.htpasswd;

    # enable the next two lines for ldap auth, also customize and enable ldap.conf in the default conf
    #auth_request /auth;
    #error_page 401 =200 /login;

    include /config/nginx/proxy.conf;
    resolver 127.0.0.11 valid=30s;
    set $upstream_beets beets;
    proxy_pass http://$upstream_beets:8337;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Scheme $scheme;
    proxy_set_header X-Script-Name /beets;
}