i am trying to deploy an app on Kubernetes pods locally on minikubes. i am having trouble with nordport and accessing my frontend

i added this to config.js of my react app

window.RUNTIME_CONFIG = {
  BACKEND_URL: "${BACKEND_URL}"
};

and am using it in the app like so

const x = window.RUNTIME_CONFIG.BACKEND_URL;

i also have an entrypoint.sh

#!/bin/sh
set -e

if [ -f /usr/share/nginx/html/config.js ]; then
  envsubst '${BACKEND_URL}' < /usr/share/nginx/html/config.js > /tmp/config.js
  mv /tmp/config.js /usr/share/nginx/html/config.js
fi

exec nginx -g 'daemon off;'

and this is my dockerfile

# build
FROM node:18.19.1 AS build
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
RUN npm run build

# runtime
FROM nginx:alpine
# install envsubst
RUN apk add --no-cache gettext
COPY --from=build /app/build /usr/share/nginx/html
COPY public/config.js /usr/share/nginx/html/config.js
COPY entrypoint.sh /entrypoint.sh
RUN chmod +x /entrypoint.sh
EXPOSE 80
CMD ["/entrypoint.sh"]

to enable cors in the backend i have a set a list of allowed ips

var allowedOrigins = map[string]bool{
    "http://localhost:3000":  true,
    "http://localhost:30100": true,
    os.Getenv("CLIENT_IP"):   true,
    
    "http://:30100": true,
    "http://app-service:3000":   true,
}

these are the ports in my frontend service

ports:
    - protocol: TCP
      port: 3000
      targetPort: 80
      nodePort: 30100

and i have env variable in my frontend deployment

env:
- name: BACKEND_URL
  value: http://server-service:8081

but i nothing is showing up on :30100. i am new to this and would appreciate some help