First of all I am beginner in programming, so if I am missing something obvious, please excuse me.
So I have been following this guide: https://www.pythonanywhere.com/wiki/VirtualEnvForNewerDjango
I have created a virtualenv for my flask app written with python3.4 as described in there https://www.pythonanywhere.com/forums/topic/1432/
Then with pip freeze I have installed the libraries.
However, I can't deploy my app as it is shown in guide, because there is no "activate_this.py" file in virtualenv forlder.
EDIT: i have made a copy of activate_this.py from a venv of lower python version and put it inside my venv 3.4 folder and it seems to work.