check
Reads the live remaining balance of one gift card from the merchant.
Every call is billed. Issue it only from an explicit member action - never on screen load, refresh or retry - and only for cards whose ActivePerksGiftCard.balanceCheck is true; the rest of the merchants do not support the lookup.
Return
The ActivePerksGiftCardBalance. A returned value with isSuccess = false is a merchant-side refusal, not a transport failure.
Parameters
order
Order line id from ActivePerksGiftCard.orderNumberDetail.
Throws
if the request fails.