Do the following

docker-compose pull

docker-compose run --rm backend --shell
Starting workshop-intro_mongodb_1 ... done
===> Environment: development
===> Current dir: /app
===> Python version: Python 3.7.3
===> Run permissions check [OK]
===> Running: gosu app bash
app@app:/app$ pip install -r requirements.txt
app@app:/app$ python src/main.py
✅ You have aiohttp installed
✅ You have BeautifulSoup4 installed
✅ You can access mongodb

You are Awesome! 👏🏼