Comment by shpx

On macOS almost everyone uses the homebrew package manager https://brew.sh. Installing bash is harder because you have to add the filepath of the new bash binary to /etc/shells and then set that filepath as your default shell, but

    brew install bash
    echo /usr/local/bin/bash | sudo tee -a /etc/shells
    chsh -s /usr/local/bin/bash

and if you're on macOS and still haven't heard of homebrew, you first need to install it with

    /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"