Docker container quit unexpectedly...(Error in deploying docker to Elastic Beanstalk) - dockerfile

Question

I am trying to deploy a docker container to Elastic Beanstalk in AWS. I'm repeatedly getting error while doing so and each time the error is related to the ENTRYPOINT that I specified in the dockerrun.aws.json. What am I doing wrong here ?
The webapp uses Django, python3 and keras.
This is my Dockerfile content:
# reference: https://hub.docker.com/_/ubuntu/
FROM ubuntu:18.04
RUN apt-get update && apt-get install \
-y --no-install-recommends python3 python3-virtualenv
# Adds metadata to the image as a key value pair example LABEL
version="1.0"
LABEL maintainer="Amir Ashraff <amir.ashraff#gmail.com>"
##Set environment variables
ENV VIRTUAL_ENV=/opt/venv
RUN python3 -m virtualenv --python=/usr/bin/python3 $VIRTUAL_ENV
ENV PATH="$VIRTUAL_ENV/bin:$PATH"
# Install dependencies:
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt
# Open Ports for Web App
EXPOSE 8000
WORKDIR /manage.py
COPY . /manage.py
RUN chmod +x /manage.py
ENTRYPOINT [ "python3" ]
CMD [ "python3", "manage.py runserver 0.0.0.0:8000" ]
And this is the dockerrun.aws.json content:
{
"AWSEBDockerrunVersion": "1",
"Ports": [
{
"ContainerPort": ""
}
],
"Volumes": [
{
"HostDirectory": "/~/aptos",
"ContainerDirectory": "/aptos/diabetes_retinopathy_recognition"
}
],
"Logging": "/aptos/diabetes_recognition",
"Entrypoint": "/opt/venv/bin/python3",
"Command": "python3 manage.py runserver 0.0.0.0:8000"
}
And this is the error from AWS logs:
Docker container quit unexpectedly on Tue Aug 20 13:03:47 UTC 2019:
/opt/venv/bin/python3: can't open file 'python3': [Errno 2] No such file
or directory.