RailsTutorial.org Learning Rails 5.3.4 Layout link test

The links in the header won't work. The code from the header file is below.

What am I doing wrong? Where's my mistake? Please help.

Here's the code for the app/views/layouts/_header.html.erb file:

' <header class="navbar navbar-fixed-top navbar-inverse">
<div class="container">
<%= link_to "sample app", root_path, id: "logo" %>
<nav>
<ul class="nav navbar-nav navbar-right">
<li><%= link_to "Home", root_path %></li>
<li><%= link_to "Help", help_path %></li>
<li><%= link_to "Log in", '#' %></li>
</ul>
</nav>
</div>
</header>