Not able to install python3-venv on Ubuntu

Question

I'm using python 3.6.9 on Ubuntu 18.04

$ sudo apt-get install python3-venv

Reading package lists... Done

Building dependency tree       
Reading state information... Done

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

The following information may help to resolve the situation:

The following packages have unmet dependencies:

 python3-venv : Depends: python3.6-venv (>= 3.6.5-2~) but it is not going to be installed
                Depends: python3 (= 3.6.5-3) but 3.6.7-1~18.04 is to be installed

E: Unable to correct problems, you have held broken packages.