I am a newbie in developing a portal for serving static files. I want to configure nginx to server static files based on user authentication. For user1 I want to be able to see only file1 For user2 I want to be able to see only file2

My current nginx configuration is:
# For more information on configuration, see:
#   * Official English Documentation: http://nginx.org/en/docs/
#   * Official Russian Documentation: http://nginx.org/ru/docs/

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    # Load modular configuration files from the /etc/nginx/conf.d directory.
    # See http://nginx.org/en/docs/ngx_core_module.html#include
    # for more information.
    include /etc/nginx/conf.d/*.conf;

    server {
        listen       80 default_server;
        listen       [::]:80 default_server;
        server_name  _;
        root         /usr/share/nginx/files;
        autoindex on;

        # Load configuration files for the default server block.
        include /etc/nginx/default.d/*.conf;

        location / {
        try_files $uri $uri/ =404;
        auth_basic "Restricted Content";
        auth_basic_user_file /etc/nginx/.htpasswd;
        }

        error_page 404 /404.html;
            location = /40x.html {
        }

        error_page 500 502 503 504 /50x.html;
            location = /50x.html {
        }
    }

[root@webportal files]# pwd
/usr/share/nginx/files
[root@webportal files]# ls -al
total 4
drwxr-xr-x. 2 root root 32 May  5 10:08 .
drwxr-xr-x. 5 root root 46 May  5 09:27 ..
-rw-r--r--. 1 root root  4 May  5 09:45 1.txt
-rw-r--r--. 1 root root  0 May  5 10:08 2.txt

Can you guys advise on what would be the simplest way to assign file 1.txt to user1 and 2.txt to user2? Basically, when one of the users authenticates on the portal he only has access to one of the file