Exporting a single content type does not contain field definitions

When I try to export a custom content type using Drupal 8 core single import/export system,(/admin/config/development/configuration/single/export) It just exported the name, type and dependency etc...

Does n't contain the custom fields that I added on the content type.

How can I export a custom content type as it is, with all fields and fields detail.

Export file.

uuid: b4bd8bda-2b1c-4b54-8b00-c23281b31768
langcode: en
status: true
dependencies:
module:
- menu_ui
third_party_settings:
menu_ui:
available_menus:
- main
parent: 'main:'
name: 'Portal News'
type: portal_news
description: 'A news entry for the portal site.'
help: ''
new_revision: false
preview_mode: 1
display_submitted: false

Please help me.