How to use different levels?

I don't get how to use different header level. I set levels to [2, 3, 4] in config but this doesn't work. I still see only single "Header" option in a toolbar. The demo at the homepage doesn't have different header levels as well.

I have the same issue

This article may help

https://codex.so/editorjs-toolbox

same...Thinking about switching to another editor