old_contents: from django.contrib import admin
  
  # Register your models here.
  
new_contents: from django.contrib import admin
  from bids_app.models import Channel, Campaign
  
  
  class CampaignInline(admin.StackedInline):
      model = Campaign
  
  class ChannelAdmin(admin.ModelAdmin):
      model = Channel
      inlines = [CampaignInline]
  
  
  admin.site.register(Channel, ChannelAdmin)
  admin.site.register(Campaign)
subject: Configure admin