An order minimum specifies the minimum amount a brand is willing to sell to a retailer. If you do not reach the minimum requirement, then you will not be able to place your order.
Please know the minimum is set by the brands themselves. You will notice that this amount varies depending on the specific brand. Please see highlighted below for reference.
As you add items to your cart while shopping for a brand, you will be shown whether you are meeting their minimum order amount or not. By adding more items to your cart, you will become closer to meeting this minimum and once you reach the limit you’ll be able to pay for this at checkout page.