File not found Nginx PHP

[OpenSource03]

I have an issue trying to create a separated demo location.

I have panel.example.com on /var/www/panel. I want panel.example.com/demo to lead to /var/www/demo.

I have the following configuration:

server {
    server_name panel.example.com;

    root /var/www/panel/public;
    index index.html index.htm index.php;
    charset utf-8;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    location = /favicon.ico { access_log off; log_not_found off; }
    location = /robots.txt  { access_log off; log_not_found off; }

    access_log off;
    error_log  /var/log/nginx/pterodactyl.app-error.log error;

    # allow larger file uploads and longer script runtimes
    client_max_body_size 100m;
    client_body_timeout 120s;

    sendfile off;

    location /demo {
        alias /var/www/demo/public;
        index index.html index.htm index.php;
        try_files $uri $uri/ /index.php?$query_string;

        location ~ \.php$ {
            fastcgi_split_path_info ^(.+\.php)(/.+)$;
            fastcgi_pass unix:/run/php/php8.0-fpm.sock;
            fastcgi_index index.php;
            include fastcgi_params;
            fastcgi_param PHP_VALUE "upload_max_filesize = 100M \n post_max_size=100M";
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            fastcgi_param HTTP_PROXY "";
            fastcgi_intercept_errors off;
            fastcgi_buffer_size 16k;
            fastcgi_buffers 4 16k;
            fastcgi_connect_timeout 300;
            fastcgi_send_timeout 300;
            fastcgi_read_timeout 300;
        }
    }

    location ~ \.php$ {
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass unix:/run/php/php8.0-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param PHP_VALUE "upload_max_filesize = 100M \n post_max_size=100M";
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param HTTP_PROXY "";
        fastcgi_intercept_errors off;
        fastcgi_buffer_size 16k;
        fastcgi_buffers 4 16k;
        fastcgi_connect_timeout 300;
        fastcgi_send_timeout 300;
        fastcgi_read_timeout 300;
    }

    location ~ /\.ht {
        deny all;
    }

    listen 443 ssl; # managed by Certbot
    ssl_certificate ...; # managed by Certbot
    ssl_certificate_key ...; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot


}
server {
    if ($host = panel.example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    listen 80;
    server_name panel.example.com;
    return 404; # managed by Certbot


}

What should be changed on location /demo to make it work? I'm constantly getting File not found. error visiting this location.

Here's error from error_log /var/log/nginx/pterodactyl.app-error.log error;

2022/10/01 14:05:38 [error] 3035080#3035080: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:41 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:42 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:43 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:43 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:43 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:43 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:43 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:43 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"
2022/10/01 14:12:44 [error] 3037423#3037423: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 172.68.51.29, server: panel.example.com, request: "GET /demo/ HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.0-fpm.sock:", host: "panel.example.com"