square.onLoyaltyProgramUpdated subscribes to loyalty.program.updated for the selected seller. It requires LOYALTY_READ.
Example
automations/square-on-loyalty-program-updated.automation.ts
Event
A loyalty program was updated. Loyalty programs can only be updated from the Square Dashboard. The signal resolves to the officialSquare.LoyaltyProgramUpdatedEvent payload with type narrowed to loyalty.program.updated.