Ruby on rails add user references to company and display an email instead of an object in active admin

activeadmin_add_user_references_to_company.rb

ActiveAdmin.register Company do
  permit_params :user_id, :name ## Add this line


  form do |f|
    f.inputs "Admin Details" do
      f.input :user_id, as: :select, collection: User.all.map { |a| [a.email, a.id] }
      f.input :name

      f.actions
    end
  end
end