sudo apt install python3-pip
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python3.9 get-pip.py
Installation
Step 1 - Update system
$$$ sudo apt-get update
Step 2 - Install pip3
$$$ sudo apt-get -y install python3-pip
Step 3 - Verification
$$$ pip3 --version
sudo apt install python3-pip