opencase/modules/opencase_cases/opencase_cases.links.action.yml

entity.oc_case.add_form:
  route_name: entity.oc_case.add_page
  title: 'Add Case'
  appears_on:
    - entity.oc_case.collection
entity.oc_case_type.add_form:
  route_name: entity.oc_case_type.add_form
  title: 'Add Case type'
  appears_on:
    - entity.oc_case_type.collection

entity.oc_actor_case_relation.add_form:
  route_name: entity.oc_actor_case_relation.add_page
  title: 'Add Actor-Case Relation'
  appears_on:
    - entity.oc_actor_case_relation.collection
entity.oc_actor_case_relation_type.add_form:
  route_name: entity.oc_actor_case_relation_type.add_form
  title: 'Add Actor-Case Relation type'
  appears_on:
    - entity.oc_actor_case_relation_type.collection