Link doesn't appear in configuration

Question

I'm a Drupal 8 newbie writing my first module. I have a functioning yet basic module to learn from. What I'm working on now is for it to get a value from a configuration page. If I go directly to the URL for the custom config page it works. What I'm having trouble with is getting a link to my custom config page to display on the main config page. I've been through every tutorial I can find on this topic and I just can't figure out why it's not working. I hope you all can help. Here's my yml files.

itemrequest.info.yml

name: Item Request
type: module
description: Allow the public to request items for the District to purchase.
package: YCFLD
core: 8.x
configure: itemrequest.settings

itemrequest.routing.yml

itemrequest.itemrequest:
  path: '/itemrequest'
  defaults:
    _controller: '\Drupal\itemrequest\Controller\ItemrequestController::itemrequestpage'
    _title: 'Request an Item'
  requirements:
    _permission: 'access content'
itemrequest.settings:
  path: '/admin/config/itemrequest/settings'
  defaults:
    _form: '\Drupal\itemrequest\Form\ItemrequestForm'
    _title: 'Item Request'
  requirements:
    _permission: 'access administration pages'
  options:
    _admin_route: TRUE

itemrequest.links.menu.yml

itemrequest.settings:
  title: 'Item Request Form'
  description: 'Settings for Item Request form"
  route_name: itemrequest.settings
  parent: system.admin_config

Do see anything wrong in the .yml files? Is there anything I can do to troubleshoot this?

Answer 1

system.admin_config is the top-level page at /admin/config. Normally you would not put your configuration link there - you would instead put it into one of the blocks that appear on that page. For example, the "People" block would be user.admin_link, so if you want your config under "People" use user.admin_link as your parent. Or if you want to put your configuration link under the "Development" block use system.admin_config_development as your parent.

If you want to create your own top-level block then you need to do things a little differently - see the core user module and how it defines user.admin_link in user.links.menu.yml and user.routing.yml - this shows how a new block is created on the config page. You can then put your configuration link in that new block.