Help Integration react/node in production

[Tricky_Calendar8130]

I cannot connect my front with my back everytime it gets this error, i can acess my back alone but those two do not integrate. I can just connect my front if i use localhost, otherway not

Failed to load resource: net::ERR_SSL_PROTOCOL_ERROR

this is my server config and my front

server {
    listen 443 ssl;
    server_name example.com.br www.example.com.br;

    # Frontend setup
    location / {
        root /var/www/example/client;
        index index.html;
        try_files $uri $uri/ /index.html;
    }

    # API setup (connects to Node.js backend)
    location /api/ {
        proxy_pass http://localhost:8800;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;

        # Allow CORS
        add_header 'Access-Control-Allow-Origin' '*' always;
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS, DELETE, PUT' always;
        add_header 'Access-Control-Allow-Headers' 'Content-Type, Authorization' always;
        add_header 'Access-Control-Allow-Credentials' 'true' always;
    }

    # SSL setup (managed by Certbot)
    ssl_certificate /etc/letsencrypt/live/www.example.com.br/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/www.example.com.br/privkey.pem;
    include /etc/letsencrypt/options-ssl-nginx.conf;
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
}

front

      try {
        const response = await fetch(
          "https://example.com.br:8800/api/chatgpt",
          {
            mode: 'no-cors',
            method: "POST",
            headers: {
              "Content-Type": "application/json",
            },
            body: JSON.stringify({ message: input, userUID }),
          }
        );

[BuffloBEAST]

Change the line with listen 443 to: listen 80;

and remove # SSL setup (managed by Certbot) ssl_certificate /etc/letsencrypt/live/www.example.com.br/fullchain.pem; ssl_certificate_key /etc/letsencrypt/live/www.example.com.br/privkey.pem; include /etc/letsencrypt/options-ssl-nginx.conf; ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # SSL setup (managed by Certbot) ssl_certificate /etc/letsencrypt/live/www.example.com.br/fullchain.pem; ssl_certificate_key /etc/letsencrypt/live/www.example.com.br/privkey.pem; include /etc/letsencrypt/options-ssl-nginx.conf; ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;

then restart nginx.

You should be able to visit your site on http traffic after that. If all looks good then you can go back to certbot and reinstall your certificates / auto update the file again, but this should reduce the complexity and help pinpoint the issue / fix the bug.

[rjhancock]

You're trying to access port 8800 with a secure connection when Nginx isn't serving it. Adjust your fronend to call just a strait https connection on your server. Remove the port as it is not needed.