Rails 5.2 can not pagination with kaminari and notifications - notifications

Question

Some of my gemfiles :
gem 'rails', '~> 5.2'
gem 'notifications', '~> 0.6.0'
gem 'kaminari'
My notifications_controller.rb like this:
# notifications_controller.rb
module Notifications
class NotificationsController < Notifications::ApplicationController
def index
#notifications = notifications.includes(:actor).order("id desc").page(params[:page])
unread_ids = #notifications.reject(&:read?).select(&:id)
Notification.read!(unread_ids)
#notification_groups = #notifications.group_by { |note| note.created_at.to_date }
end
def clean
notifications.delete_all
redirect_to notifications_path
end
private
def notifications
raise "You need reqiure user login for /notifications page." unless current_user
Notification.where(user_id: current_user.id)
end
end
end
My routes.rb about notifications like this :
mount Notifications::Engine, at: "notifications"
My index.html about notifications like this:
# notifications/notifications/index.html.erb
<div class="paginationBox">
<%= paginate #notifications,left:2,right:1,window: 1 %>
</div>
With the above codes , I can get the right notifications , but I can not paging the all notifications. I had the error like this:
NoMethodError - undefined method `total_pages' for #<Notification::ActiveRecord_Relation:0x00007fcfacae6dd8>:
app/views/notifications/notifications/index.html.erb:33:in `_app_views_notifications_notifications_index_html_erb__2430601159943313679_70264929101860'
If I change the action index of notifications_controller.rbto
#notifications = notifications.includes(:actor).order("id desc").page(params[:page]).per(10)
I get the same error undefined method total_pages....
If I just change the index.html.erb of notificaitons to
<div class="paginationBox">
<%= paginate#notifications.page(params[:page]).per(10),left:2,right:1,window: 1 %>
</div>
It does not display any errors ,but the kaminari can not paging the all notifications .
So ,where did I had the errors? Could you please help me ? Thanks so much!