square.onLoyaltyAccountUpdated subscribes to loyalty.account.updated for the selected seller. It requires LOYALTY_READ.
Example
automations/square-on-loyalty-account-updated.automation.ts
Event
A loyalty account was updated. For example: The seller updates the phone number registered for the loyalty account using the Square Dashboard. For more information, see Square Loyalty FAQ . Any change in the loyalty point balance, such as points added for visits, points expiration, or a manual adjustment to the point balance that a seller might perform. The customer ID of the loyalty account was changed. For example, the loyalty account moved to another customer. The signal resolves to the officialSquare.LoyaltyAccountUpdatedEvent payload with type narrowed to loyalty.account.updated.