Support for M1 macs
When installing using Homebrew on an M1 mac, the completion is installed to /opt/homebrew/share/zsh/site-functions so some additional setup might be needed.
I think it should work fine, assuming you have eval $(brew shellenv) in your Zsh configuration:
To make Homebrew's completions available in zsh, the Homebrew-managed zsh/site-functions path needs to be inserted into FPATH before initialising zsh's completion facility. This is done by brew shellenv, so if you followed the post-Homebrew installation steps, eval "$(brew shellenv)" should be in your ~/.zprofile (on macOS) or ~/.zshrc (on Linux). All you need is add the following to your ~/.zshrc if it's not already there, and, if you're on Linux, make sure it's placed after eval "$(brew shellenv)":
Fixed with upcoming release