https://traversal.ist/how-to-authenticate-anonymous-users-in-rails - routes

routes.rb

Rails.application.routes.draw do
  get 'users/anon', to: 'users#anon'
  get 'users/current', to: 'users#current'
  post 'users/login', to: 'users#login'
  resources :users, only: [:create]
end