drupal/core/modules/node/node.links.action.yml

node.type_add:
  route_name: node.type_add
  title: 'Add content type'
  appears_on:
    - entity.node_type.collection
node.add_page:
  route_name: node.add_page
  title: 'Add content'
  appears_on:
    - system.admin_content