unable to load CSS style images when deploy angular coreui in off root Nginx

[samminen]

I deployed my coreui angular app in ngnix as off root deployment. When i launch the App URL, I see few images ( rendered from CSS classes as shown below) not rendering in the UI.

CSS Class to render image:
.icon-speech {
content: "\e02c" !important;
}

Ngnix config file:

server {
#-------

location /rig-activity {

    set $url http://edge_rig-activity-service;
                rewrite ^/rig-activity(.*) $1 break;
                proxy_pass $url;
        }

        location /rig-activity-ui/ {
            #enable for debug mode
            #proxy_pass http://localhost:4200;


            #root /www/html;
            alias /www/rig-activity-ui/;

            #index  index.html index.htm;

            try_files $uri$args $uri$args/ $uri/ /rig-activity-ui/index.html;
        }

}