To add a header to your text:
Highlight the text you want to change to a header.
Click the Format dropdown menu in the editor.
If nothing has been set for the current text, this will display Paragraph in the box.
Select Headers.
Select the header level you want to use from the options.
If you find that your headers are not applying to some text, it may be due to there being some HTML code already wrapped around the text.
This will be visible in the Source Code editor, however, the simplest way to resolve this is to delete the entire line of text, and re-type it. Cutting the text and pasting it back in will not work.
📌 Note: It’s best to use headers consistently across your site and in a structured order (e.g. you shouldn't use Header 2 and then jump to a Header 4 without using a Header 3 in between).