Your vendor got your order. They had the option to either accept or reject your order.
Your order was accepted by your vendor. You should expect the order to arrive on said date/time. If you would like to adjust the order, click on the order and adjust it right in the app.
Your order was rejected by your vendor. Your vendor found an issue with the order. Hopefully they responded to you in shelf as to why they didn't accept the order. Otherwise, please reach out to your vendor.