Noted: Local installation of Python is recommended to avoid conflicting the system-wide Python version.
$ apt-get install python3-venv
Command: python3.8 -m venv <virtual-environment-name>
$ python3.8 -m venv my-venv
$ source my-env/bin/activate
(my-env) $ python -V
Python 3.8.3
(my-env) $