square.onCustomerCustomAttributeOwnedUpdated subscribes to customer.custom_attribute.owned.updated for the selected seller. It requires CUSTOMERS_READ.
Example
automations/square-on-customer-custom-attribute-owned-updated.automation.ts
Event
A custom attribute owned by your application was created or updated for a customer profile. This event replaces the deprecated customer.custom_attribute.updated event. The signal resolves to the officialSquare.CustomerCustomAttributeOwnedUpdatedEvent payload with type narrowed to customer.custom_attribute.owned.updated.