How do I install apt on Ubuntu? [duplicate]

I'm trying to install Google authenticator on Ubuntu.

I tried sudo apt install libpam-google-authenticator which results in the error sudo: apt: command not found. Shouldn't apt already be installed on Ubuntu? I have tried several commands with apt. Beware I am very new to Linux.

When I use the command lsb_release -a this is the output:

-bash: lsb_release: command not found

I installed "Ubuntu 20.04 LTS" from the Microsoft Store.

When I use the command cat /etc/os-release this is the output:

NAME="CentOS Linux"VERSION="8"ID="centos"ID_LIKE="rhel fedora"VERSION_ID="8"PLATFORM_ID="platform:el8"PRETTY_NAME="CentOS Linux 8"ANSI_COLOR="0;31"CPE_NAME="cpe:/o:centos:centos:8"HOME_URL="https://centos.org/"BUG_REPORT_URL="https://bugs.centos.org/"CENTOS_MANTISBT_PROJECT="CentOS-8"CENTOS_MANTISBT_PROJECT_VERSION="8"

$: echo $PATH/home/mkristiansen/.local/bin:/home/mkristiansen/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin