JSFiddle - React, Tailwind, and code Playground

HTML

<div id="hide">Hide</div>
        <div id="header" class="ToBeShowed">This is a fixed header</div>

JavaScript

$("#hide").click(function() {
      $(".ToBeShowed").fadeToggle("slow", "linear");        
        
            if ($(this).text() == 'Hide') {
                $(this).text('Show');
            }
            else {                
                $(this).text('Hide');
            }
        });
    });
    
    if ($(".ToBeShowed").is(':visible')) 
    {
          $("#hide").html("Click to hide");
    }
    if ($(".ToBeShowed").is(':hidden')) 
    {
          $("#hide").text("Click to show");
    }