Using WP theme 2017 I want to add MaxButtons to the Header Media photo.

[ Moderator note: moved to Fixing WordPress. Please do not use Developing With WordPress for these topics. ]

Using WP theme 2017 I want to add MaxButtons to the Header Media photo that is on the landing page. The short code,(an example here that MaxButtons generates for a new button [maxbutton id=”1″]) is a CSS pointer that their generator instructs one to add it to one of opening tags in the HTML portion of the theme. Some assistant instructor from a WP instruction class suggested that I put it in the header.php file. But where? I’ve tried there and in the front-page.php file, but no luck getting it to appear on the top portion of the landing page.