📚 How to find my system default package manager in bash script?

Hey everyone, a new linux user here. I switched to linux few months back and I started out with linux mint. While looking for linux tips I found out that I can changed my shell preference, an I switched to zsh from bash. But I didn't want to lose my configuration for my bashrc and other bash files, so I started to look for how to backup the configuration for bash and discovered concept called dotfile & symlink.

Fast forward few weeks and I'm writing a bash script to automate installation and configuration for my preferred apps. As mint's package manager I wrote script for apt or apt-get (I personally use apt).

And I want to write that script as system independent as possible if in future I ever switch to different distro(for example Arch). My script wouldn't be limited by system.

So, how can I configure my bash script to be system indi?

: Thanks for replies.