How to hide the (1) from the navigation bar when using annotations in a header?

[laikrai]

[squidfunk]

You can pass an explicit table of contents label, if Attribute Lists is enabled:

## Join (1) { data-toc-label="Join" }

Other than that, using annotations in headlines might not be the best idea. We've just added footnote tooltips, which have better Markdown support than annotations as they degrade more gracefully.

[kamilkrzyskow]

The screenshot shows the integrated table of contents, so the toc-item.html partial is responsible for rendering it.
Additionally to the above the (1) can be removed via some context filter (jinja should have access to str functions) in a template override:
https://squidfunk.github.io/mkdocs-material/customization/#extending-the-theme

mkdocs-material/src/templates/partials/toc-item.html

Line 27 in f55ce2c

{{ toc_item.title }}

Otherwise the page.toc can be modified by an MkDocs hook in the on_page_context event to remove the (1) from the title:
https://www.mkdocs.org/user-guide/configuration/#hooks
https://www.mkdocs.org/dev-guide/plugins/#on_page_context