Problem with login and logout link

_navbar.html.erb

<nav class="navbar sticky-top navbar-expand-lg navbar-dark bg-danger">
    <div class="container">
        <%= link_to root_path do%>
            <%= image_tag ('Ruby_On_Rails_Logo.svg'), width: 100 %>
        <% end %>
        
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent"
            aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
        </button>

        <div class="collapse navbar-collapse" id="navbarSupportedContent">
            <ul class="navbar-nav ml-auto">
                <li class="nav-item active">
                    <%= link_to 'Home', root_path, class: 'nav-link' %>
                </li>
                <li class="nav-item">
                    <%= link_to 'About', about_path, class: 'nav-link' %>
                </li>
                <li class="nav-item">
                    <%= link_to 'Contact', contact_path, class: 'nav-link' %>
                </li>
                <li class="nav-item">
                    <%= link_to 'Blog', articles_path, class: 'nav-link'%>
                </li>
                <% if logged_in? %>
                    <li class="nav-item">
                        <%= link_to 'Log Out', logout_path, method: :delete, class: 'nav-link'%>
                    </li>
                    <li class="nav-item dropdown">
                        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true"
                            aria-expanded="false">
                            Dropdown
                        </a>
                        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
                            <a class="dropdown-item" href="#">Action</a>
                            <a class="dropdown-item" href="#">Another action</a>
                            <div class="dropdown-divider"></div>
                            <a class="dropdown-item" href="#">Something else here</a>
                        </div>
                    </li>
                <% else %>
                    <li class="nav-item">
                        <%= link_to 'Log In', login_path, class: 'nav-link'%>
                    </li>
                    <li class="nav-item">
                        <%= link_to 'Sign Up', signup_path, class: 'nav-link'%>
                    </li>
                <% end %>
            </ul>
        </div>
    </div>
</nav>

application_controller.rb

class ApplicationController < ActionController::Base
    
    helper_method :current_user, :logged_in?

    def current_user
       @current_user ||= User.find(session[:user_id]) if session[:user_id]
    end

    def logged_in?
        !!current_user
    end

    def require_user
        if !logged_in?
            flash[:danger] = "You must be logged in to perform that action."
            redirect_to root_path
        end
    end

end

sessions_controller.rb

class SessionsController < ApplicationController
    def new
    end

    def create
        user = User.find_by(email: params[:session][:email].downcase)
        if user && user.authenticate(params[:session][:password])
            session[:user_id]
            flash[:success] = "You have successfully logged in."
            redirect_to user_path(user)
        else
            flash.now[:danger] = "There was something wrong with the login information."
            render 'new'
        end
    end

    def destroy
        session[:user_id] = nil
        flash[:success] = "You have logged out."
        redirect_to root_path
    end
end