Why everytime I need to install Flask

Question

Hi guys.
I am learning Flask with Python. When I creating new project and type 'from flask import Flask' it shows no flask on it. So everytime I need to do 'pip install flask' on PyCharm.
I thought if I did once, so it'll be always on PyCharm, but now on every single new project I need to repeat that. Any thoughts or concerns?
Thank you