widget activation

> My site susannahmakram.com is in fludial theme that supports widget. No codes I
> try to add to theme php enable a search (site/text in site) box. This is what
> I’m trying to add. I added a widget to the homapegae but this is not working
> either. Is there a code or way to add a search box that stays in the header of
> site for functional navigation? Thank you