can't import attachments when we install custom app with exported doctypes

after exporting erpnext doctype (included attachments) into custom app using fixtures and pushed into github. in production bench after clone that custom app and while installing that custom app it is showing this error.

      file_path = './n.com/public/files/images.jpeg'
builtins.FileNotFoundError: [Errno 2] No such file or directory: './n.com/public/files/images.jpeg'

as per my understanding attachments cant able to import how can we solve this and how we can import attachment into production system and what doctype should i export in order to get attachments into production system.