How to install packages in a virtual environment?

Question

Python

The bottom line is this:
the ubuntu 16 system
installed python 3.7.4
created a virtual environment, activated
it further when trying to install any package, I get

Could not install packages due to an EnvironmentError: [Errno 13] P
ermission denied: '/home/rokealvo/projects/pdf2tiff/venv/lib/python
3.7/site-packages/click'
Consider using the `--user` option or check the permissions.

having read

Consider using the `--user` option or check the permissions.

and scrolling through google added --user
, the installation itself passes without errors, but when the application is launched, python does not see the modules.
where to dig?

Answer 1

Toward permissions on the venv directory. It looks like you created it somehow crookedly, this should not be.