You will find the site sub-header customization option inside:
Dashboard > Appearance > Customize > Site Sub Header.
- Customize Background – This allows you to set subheader background color or image.
- Content Typography – This allows you to set header content typography.
- Site Breadcrumbs – This allows you to set breadcrumb on the subheader.
![](https://knowxtheme.com/wp-content/uploads/2021/02/sub-header-setting-1024x499.png)