Blank page when running with nginx reverse proxy

I’m running rocket chat server with nginx as reverse proxy
When I go in to http://my-ip:3000, it works
When I go in to http://my-ip/rocket, it give me a blank page


Below is my /etc/nginx/sites-available/default file content, what did I do wrong? how could I fix it?

server {
    listen 80 default_server;
    listen [::]:80 default_server;
    root /var/www/html;
    index index.html index.htm index.nginx-debian.html;
    server_name _;
    location / {
        try_files $uri $uri/ =404;
    }

    location /rocket {
      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 $http_host;
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Forward-Proto http;
      proxy_set_header X-Nginx-Proxy true;
      proxy_redirect off;
    }
}