Html
<html>
<!-- title -->
<head>
<meta charset="utf-8">
<title>Example</title>
</head>
<body>
<!-- connect library jQuery -->
<script src="https://dir.by/example_lib/jquery/jquery-3.3.1.min.js"></script>
<!-- connect library Bootstrap (js file) -->
<script src="https://dir.by/example_lib/bootstrap-4.1.3/js/bootstrap.min.js"></script>
<!-- connect library Bootstrap (css file) -->
<link rel="stylesheet" href="https://dir.by/example_lib/bootstrap-4.1.3/css/bootstrap.min.css">
<!-- form -->
<form class="form-inline">
<input type="text" class="form-control mr-sm-2" placeholder="Search">
<button type="submit" class="btn btn-default">Click me</button>
</form>
</body>
</html>