Having trouble getting started with the devise invitable gem

Getting a No route matches [GET] “/users/invitation/new” error even though it the /invitation/new new_user_invitation_path is stated under the list of routes.

Using Gem Devise Invitable and using this video for reference: Ruby on Rails #43 Gem Devise Invitable - the correct way to create or invite users to your app - YouTube

tried:

rails generate devise_invitable:install
rails db:migrate
rails generate devise_invitable:views

routes.rb:

Rails.application.routes.draw do
  # ...
  devise_for :users, controllers: { invitations: 'users/invitations' }
  # ...
end

can you share the full error backtrace? you may need to restart the server usually or make sure the app/controllers/users/invitations_controller.rb is exist too