pip install virtualenv
virtualenv {flodername} (ex. virtualenv env)
env\Scripts\activate
(env) ...
virtualenv must activate always
install in virtual only
pip install Flask
pip install requests
ngrok http {port}
For wsl
sudo apt-get install python-pip
sudo pip install virtualenv
apt-get install python3-venv
python3 -m venv {folder env}
create folder env
virtualenv -p python3 env
source env/bin/activate
exit : deactivate
pip3 freeze > requirements.txt
pip install -U flask-cors