How to get iTunes stores in Afghanistan?

Further to Jim's comment, here is what is available in the iTunes Store in Afghanistan:

Afghanistan

• App Store
  • Apple Arcade
• Shazam
• Apple TV app
  • Synced videos only
• Apple Podcasts
  • Free podcasts only

For more info, see here: ]Availability of Apple Media Services - Apple Support

It appears you are trying to use the iTunes U app. This service was shut down years ago. Are you wanting to access Music or Apps?