Web-item link custom searchbar

Hi there, We are developing jira and want implement new search bar left from default searchbar.
I have found just as add web-item (which is a link). However I can’t find way how to customize
it as form with input and style aui-quicksearch. Sure, I can attach resources but don’t know how
to make default link like my customized searchbar. I imagine it as some form with JS which call my rest.