nginx: nginx: [emerg] "upstream" directive is not allowed here in /etc/nginx/sites-enabled/www.example.com.conf

Question

Please, can anyone help me? I'm having to do a load balance on a reverse proxy server, which was not configured by me. And when I configure the upstream directive it is giving an error. I have already tried to set it within http {} and within the settings of the site included.

My nginx.conf

load_module /usr/lib64/nginx/modules/ngx_stream_module.so;
user nginx;
worker_processes 16;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

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;

        client_max_body_size 20m;
        proxy_read_timeout 3600;

        sendfile            on;
        tcp_nopush          on;
        tcp_nodelay         on;
        types_hash_max_size 2048;

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

# Security # 

        add_header          Strict-Transport-Security "max-age=63072000; includeSubdomains";
        ssl_ciphers         "EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH";
        keepalive_timeout   750;
        server_tokens       off;
        #more_clear_headers 'Server' 'X-Powered-By' 'X-Content-Powered-By';
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
        add_header          X-Content-Type-Options nosniff;
        add_header          Content-Security-Policy "frame-ancestors digital.fortaleza.ce.gov.br epgm.pgm.fortaleza.ce.gov.br revista.pgm.fortaleza.ce.gov.br";
        add_header X-Frame-Options "ALLOW-FROM digital.fortaleza.ce.gov.br epgm.pgm.fortaleza.ce.gov.br";
        add_header          X-Frame-Options SAMEORIGIN;
        add_header          X-XSS-Protection "1; mode=block";

#Compression

        gzip on;
        gzip_proxied any;
        gzip_vary on;
        gzip_disable “MSIE [1-6]\.(?!.*SV1)”;
        gzip_disable "msie6";
        gzip_comp_level 6;
        gzip_buffers 16 8k;
        gzip_http_version 1.1;
        gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

#SSl Certificate Security


        ssl_protocols       TLSv1 TLSv1.1 TLSv1.2;
        ssl_dhparam         /etc/nginx/ssl/dhparam4096.pem;
        ssl_prefer_server_ciphers on;
        ssl_session_cache shared:SSL:10m;
        ssl_session_timeout 10m;

#Proxy

        proxy_hide_header on;
        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_set_header        X-Forwarded-Host $host;
        proxy_set_header        X-Forwarded-Server $host;

        server {
                listen 80;
                error_page 404 /404.html;
                location = /basic_status {
                        stub_status;
                        allow 172.30.50.100;
                        allow 10.0.10.100;
                        deny all;
                }
                location / {
                return 301 https://www.example.com.br;
                }
    
        }
        
    
        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*.conf;

}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               

My www.example.com.br config file inside sites-enable

upstream example {
    server 192.168.0.1;
    server 192.168.0.2;

}
server {

        listen   443 ssl;
        server_name www.example.com.br;
        ssl_certificate /etc/nginx/certificates/bundle-pgm.crt;
        ssl_certificate_key /etc/nginx/certificates/privatekey.key;

        access_log /var/log/nginx/www.example.com.br/www.example.com.br_access.log;
        error_log /var/log/nginx/www.example.com.br/www.example.com.br error;

        location / {
            proxy_pass  http://example;
        }
    
    
}

server {
    if ($host = www.example.com.br) {
        return 301 https://$host$request_uri;
    }
        listen   80;
        server_name www.example.com.br;
        return 404;
}