It is not recommended to do so. First of all, AliExpress requires registered mail for all small packages. Secondly, you can fill in the delivery order number according to the format first, and then modify it to the real order number after delivery. I have done this several times, but I will modify it to a real and valid order number every time. So far, it has not been checked. If you make an order number every time, even if you guessed it right, the corresponding delivery time and the actual delivery time and destination country shown in the order number may not match. If you do it too many times, you will probably be checked. It is recommended to be honest, after all, you still have to ship the goods in the end.