Q:

i linked the boostrap.css and boostrap.min.css but style is not working

I am tring to creating the Bootstrap Navbar, I linked the boostrap.css and boostrap.min.css successfully.  but when i saw the browser it is not working in php. 
 <link type="text/css" href="bootstrap/bootstrap-4.3.1-dist/css/bootstrap.css" rel="stylesheet">
         <link type="text/css" href="bootstrap/bootstrap-4.3.1-dist/css/bootstrap.min.css" rel="stylesheet">

    <nav class="navbar navbar-inverse">
        <div class="container-fluid">
            <div class="navbar-header">
                <a class="navbar-brand" href="#">WebSiteName</a>
            </div>
            <ul class="nav navbar-nav">
                <li class="active"><a href="#">Home</a></li>
                <li><a href="#">Page 1</a></li>
                <li><a href="#">Page 2</a></li>
                <li><a href="#">Page 3</a></li>
            </ul>
        </div>
    </nav>

A:

I think you miss the head tag, thatswhy this can happen.  Put your CSS links inside the head tag. 
  <head>
    <link type="text/css" href="bootstrap/bootstrap-4.3.1-dist/css/bootstrap.css" rel="stylesheet">
     <link type="text/css" href="bootstrap/bootstrap-4.3.1-dist/css/bootstrap.min.css" rel="stylesheet">
   </head>

  <body>
   <nav class="navbar navbar-inverse">
     <div class="container-fluid">
        <div class="navbar-header">
            <a class="navbar-brand" href="#">WebSiteName</a>
        </div>
        <ul class="nav navbar-nav">
            <li class="active"><a href="#">Home</a></li>
            <li><a href="#">Page 1</a></li>
            <li><a href="#">Page 2</a></li>
            <li><a href="#">Page 3</a></li>
        </ul>
    </div>
</nav>

</body>

