get https://api-sandbox.pismolabs.io/merchants/v1/merchants//advancements/requests
List advancements requested by merchant. An advancement is the same as a receivable or a prepayment of a receivable. An example of a situation in which a seller might use advancements is if it has a deal with a large customer who it knows is going to take some time to pay its bills. To cover its business expenses in the meantime, the seller could make a deal with a bank to pay it for the goods sold at the time of sale. The seller later repays the bank when it gets paid by its customer. The bank profits because the seller pays a fee for each advancement.