Nginx reverse proxy with React App

We have a react app (SPA) running on 192.168.1.1:3000. We are also using nginx i our gateway as proxy server to access different applications running in our LAN without any issue. But not able to get this react app working with nginx proxy which may be due to the way react app works. I have tried the following config in nginx which lands me to the index page but not rendering anything (blank page).

location /test/app1/
{
rewrite ^/test/app1/ (.*) /$1 break;
proxy_pass http://192.168.1.1:3000/;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection ‘upgrade’;
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-Proto $scheme;
proxy_cache_bypass $http_upgrade;
proxy_redirect off;
}

Can anyone suggest how to get it work?

I need help