square.onCustomerCustomAttributeDefinitionOwnedUpdated subscribes to customer.custom_attribute_definition.owned.updated for the selected seller. It requires CUSTOMERS_READ.
Example
automations/square-on-customer-custom-attribute-definition-owned-updated.automation.ts
Event
A custom attribute definition owned by your application was updated. Note that only the definition owner can update a custom attribute definition. This event replaces the deprecated customer.custom_attribute_definition.updated event. The signal resolves to the officialSquare.CustomerCustomAttributeDefinitionOwnedUpdatedEvent payload with type narrowed to customer.custom_attribute_definition.owned.updated.