farm-2.x-dev/modules/core/plan/plan.links.action.yml

entity.plan.add_page:
  route_name: 'entity.plan.add_page'
  title: 'Add plan'
  appears_on:
    - entity.plan.collection

entity.plan_type.add_form:
  route_name: 'entity.plan_type.add_form'
  title: 'Add plan type'
  appears_on:
    - entity.plan_type.collection