post https://api.voucherify.io/v1/promotions//stacks
This method creates one promotion stack given promotion tier ids.
Response schema
Returns a new stack object if a valid promotion campaign identifier was provided in the path and available promotion ids in the payload.
id An internal id corresponding to the stack id.
name Contains the name of the stack.
tiers An object containing the ids of the stacked promotion tiers.
Returns an error if an incorrect campaign id or promotion id is provided.