get
https://api.campaign.episerver.net/rest//couponblocks//assignedmailings
Get all mailing IDs to which a specified coupon block is assigned.
The coupon block could not be found. Ensure that the required parameters such as "couponBlockId" are correct and the coupon block exists.
The coupon block is not assigned to the indicated client. Ensure that "clientId" and "couponBlockId" are correct and that the "couponBlockId" is assigned to the indicated client.
