I installed fish shell on macOS, so I’ll introduce the steps.

Install fish

brew install fish

which fish
/opt/homebrew/bin/fish

List of Valid Shell Full Paths for Login Shell

cat /etc/shells
# List of acceptable shells for chpass(1).
# Ftpd will not allow users to connect who are not using
# one of these shells.

/bin/bash
/bin/csh
/bin/dash
/bin/ksh
/bin/sh
/bin/tcsh
/bin/zsh

Change Login Shell to fish

sudo -e /etc/shells

Then add:

/opt/homebrew/bin/fish

chsh -s /opt/homebrew/bin/fish

Restart Terminal.app and if it’s now fish, you’re done.

Above, I installed fish shell on macOS.

That’s all from the Gemba.