Instal Python 3.9 Linux
# Want to do this first usually
sudo apt update
sudo apt install software-properties-common
# A repo for python3.9 that works
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt install python3.9
# Checking that it worked
python3.9 --version
# Now to add venv - ensurepip
sudo apt-get install python3.9-venv
sudo python3.9 -m venv <my_env_name>
Agrius