autocomplete does not show up by default

[yunhao-jiang]

I encountered this weird issue where if I don't use oh-my-zsh, the autocomplete menu won't show up, even with the configuration
zstyle ':autocomplete:*' min-input 0.
Unlike shown in the video: https://youtu.be/ZhFFs5ltNDs?si=YVjXNw0-3LuKNoK6&t=183 ,when I type brew, there is no suggestion being printed out:

Did I miss any configurations?
I installed zsh-autocomplete through homebrew, and if I enable oh-my-zsh, it works fine. But if I don't use its and just source /opt/homebrew/share/zsh-autocomplete/zsh-autocomplete.plugin.zsh, no suggestions will be printed out.