Localhost:3000 - Port forwarding not reaching

Hi All,
I am new to Docker. Now, i have created a Angular application and when i do ng serve, it is working in localhost:4200 without any issues.
Then i have created a Dockerfile inside my Angular app and then i do a docker buid to create a image and it is working. Next, i have containerize the image, that also also creating. but when i run the localhost:3000 in browser, it is not reaching. it is showing the below attached error.

My Docker file:

# Use the official Node.js image as the base image
FROM node:14

# Set the working directory

# Copy the package.json and package-lock.json files
COPY package*.json ./

# Install the required packages
RUN npm install

# Copy the rest of the application files
COPY . .

RUN npm run build


CMD [ "npm", "start" ]

My output:

Am i done anything wrong.

If you expect that EXPOSE 3000 in the dockerfile would do anything, that is wrong. It is just a metadata. Since you didn’t share how you started the container which could actually define port forwarding, I guess this is what happened.