How to customize header career site?

Summary:

Creation of header menu on career site

Content (required):

We discovered that now the Career Site has only the Minimum Template option. This option doesn't seem to allow upper button bar on the website, but only an hamburger button.

We'd like to have an upper bar with buttons. How can do it?

We tried to add the below code snipped on the Custom Header section but the result is not what expected:

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):

<a href="#" class="myButton">light grey</a>