Are you looking for a free Astra theme sticky header?
Many WordPress themes are either bare-bones or are WAY overdone, which is why I love Astra. It comes out of the box with a fair amount of options without being too much. And it’s optimized really well too. Perfectly balanced, as all things should be.
The problem with Astra is that the sticky header option is only available in the Pro version. Well, screw that! If all you need is a sticky header, then I’ve got the solution for you! All you need is a little bit of CSS, and voila!