502 bad gateway only in /

I have laravel api & nextjs admin panel runing fine but the shop in / throw 502 bad gateway

server { listen 80;

server_name proudlyai.com;

client_max_body_size 256M;

add_header X-Frame-Options "SAMEORIGIN";
add_header X-XSS-Protection "1; mode=block";
add_header X-Content-Type-Options "nosniff";

index index.html index.htm index.php;

charset utf-8;

location /backend {
    alias /var/www/proudlyai/pixer-api/public;
    try_files $uri $uri/ @backend;
        location ~ \.php$ {
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $request_filename;
        fastcgi_pass   unix:/run/php/php8.2-fpm.sock;
     }

}

location @backend { rewrite /backend/(.*)$ /backend/index.php?/$1 last; }

location /{ proxy_pass http://localhost:3000; 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; }

location /admin{
    proxy_pass http://localhost:3002/admin;
    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;
}

error_page 404 /index.php;

location ~ \.php$ {
    fastcgi_pass unix:/var/run/php/php8.2-fpm.sock;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
    include fastcgi_params;
}

location ~ /\.(?!well-known).* {
    deny all;
}

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

}