patch https://api.sandbox.cleeng.com/3.1/subscriptions/
Currently, update subscription endpoint supports the following: activating, stopping and terminating a subscription, applying coupon on an existing subscription, extending a subscription, updating payment details for a subscription.
You can only use one parameter:
expiresAt,couponCode,paymentDetailsId,status,inTrialorexternalProperties.
Response format is the same as in Create subscription endpoint.