How to activate terminal auto completion on macOS Catalina

I've just clean installed macOS Catalina and the usual way of activating auto complete does not work for me. I use the default shell zsh:

1 Type in terminal nano ~/.inputrc
2 Paste the following on separate lines

set completion-ignore-case on
set show-all-if-ambiguous on
TAB: menu-complete

3 Hit control+O to save changes to .inputrc followed by control+X to exit nano
4 Open a new Terminal window or tab to open a new session with autocomplete enabled

What am I missing?

If you have done a fresh install then you need to be aware that the default shell has changed to zsh which as I understand it doesn't read .inputrc.

So either change your default shell back in System Preferences -> Users & Groups or use .zshrc instead for your configurations