commerce-8.x-2.8/modules/store/commerce_store.links.action.yml

entity.commerce_store.add_page:
  route_name: entity.commerce_store.add_page
  title: 'Add store'
  appears_on:
    - entity.commerce_store.collection

entity.commerce_store_type.add_form:
  route_name: entity.commerce_store_type.add_form
  title: 'Add store type'
  appears_on:
    - entity.commerce_store_type.collection