Dockerfile not properly running

I have a web application written in Flask and it is working fine in localhost setup. Now i want to make it dockerized in a container and want to run it via docker. The issue is when I start the docker image it is running the same way as it is in the localhost setup. This is my Dockerfile

FROM python:3.8-slim-buster

RUN mkdir -p /home/app

#Setting up virtual environment

ENV VIRTUAL_ENV=/home/ranji/FlaskApp/venv
RUN python3 -m venv $VIRTUAL_ENV
ENV PATH="$VIRTUAL_ENV/bin:$PATH"

# Install dependencies:
COPY requirements.txt .
RUN /home/ranji/FlaskApp/venv/bin/python3 -m pip install --upgrade pip
RUN pip3 install -r requirements.txt


COPY app.py .
COPY regor_GP_20_v1.pkl .
COPY index.html .
COPY logger.sqlite3 .

# Run the application:
CMD ["python", "app.py"]

My idea is to have this in a docker container and I want to run it from there. I strongly believe that I’m missing some commands or wrongly doing something. Any help would be obliged.
Error
Bash logs

Source: Docker Questions