Not able to Login in keyrock IDM using Nginx

Question

I have installed nginx reverse proxy server and fiware keyrock IDM. I want to access fiware keyrock using Nginx server with the url https://"nginx-ip"/key

My nginx conf is as follows:

location /idm/ {
   proxy_set_header   X-Forwarded-Host    $host;
   proxy_set_header    Host                $host;
   proxy_set_header    X-Real-IP            $remote_addr;
   proxy_set_header    X-Forwarded-For        $proxy_add_x_forwarded_for;
   rewrite ^/idm(/.*)$  $1 break;
   proxy_pass           https://KEYROCK_HOST:KEYROCK_PORT;
   proxy_redirect / /idm/;
   sub_filter '="/' '="/idm/';
   sub_filter '= "/' '= "/idm/';
   sub_filter '=\'/' '=\'/idm/';
   sub_filter_once off;

 }

After configuring the nginx configuration, I am able to load/access keyrock at:

https://nginx-ip/idm.

But when I try to login it doesn't logins and shows the same homepage of keyrock IDM. I have actually done several changes at nginx end but none of it worked.

Fiware IDM : https://github.com/ging/fiware-idm/tree/7.5.1