Navigate to the Control Panel > Website Tab > Setup > Look & Feel.
In the Site Editor Toolbar, click Header/Top.
This section covers the top of your website, including your website's header, your menu if you choose a horizontal menu, and your login link if you place the login link at the top.
Remember, you must include a login link to save a version of your template. This login link can be included in any section of your website.
Row templates are available for your website's header and include a section for your logo, menu, and login link. These templates can be modified, so you can use them as a starting point when making changes to your website.
Add Rows or Row Templates, then add Widgets to your rows to build your website header.