Why can't I submit the courier number?

One possibility is that the order number has been used by others. One possibility is that this single number is not used at all. Or because of network problems, there is no way to submit the courier number, which leads to the delay. Different courier companies have different digits and different editing methods. If the courier number is entered incorrectly, it will also lead to the failure to submit the courier number. Be sure to check the express number carefully when sending it.