Mutiple model devise

controller.rb

# app/controllers/admin

class  Admin::PostController < ActionController::Base
  before_action :authenticate_admin!

  def index
    @posts = Post.all
  end
  
  def switch_user
    if admin_signed_in?
      sign_out(:admin)
      sign_in(:partner, User.first)
    end
    redirect_to api_api_index_path
  end
  
  def authenticate_admin!
    sign_out(:user) if user_signed_in?
    super
  end
end

# routes.rb
Rails.application.routes.draw do
  namespace :admin do
    resources :posts do
      post :switch_user, on: :collection
    end
  end
  devise_for :admins, path: 'admin', skip: :registrations
  
  devise_for :users
end