"Request Header Fields Too Large" error on React App

Hello Community!
I’ve created a subdomain and installed a React App on it. I’ve completed all the steps and the react app using the pm2 server is online now. but when I visit that subdomain it shows “431 Request Header Fields Too Large”. How do we resolve this error?
My configurations are given below:

  • App Type: React
  • npm, pm2 is required and installed.
  • pm2 running on port 3030

I’ve added these lines to vHost Conf:

extprocessor ezcart {
  type                    proxy
  address                 127.0.0.1:3030
  maxConns                100
  pcKeepAliveTimeout      60
  initTimeout             60
  retryTimeout            0
  respBuffer              0
}

Rewrite Rules is configured this way:

RewriteEngine On
RewriteRule ^(.*)$ HTTP://ezcart/$1 [P]

I’ve tried these exact steps in a VPS and that’s working perfectly fine without any issues. However, I’m only finding this issue only with CyberPanel.

Can anyone please help me on this issue?
Thank you.

No one can help me on this issue!?