啊，你说的对我只是看到FAQ里的下面文字 Q17: What should I input for "Vehicle Number" if I do not have the transport details before/at arrival? A: If you are travelling by rail, you may wish to submit your declaration on the same day of your arrival when you have the vehicle number. Alternatively, you may submit the declaration beforehand and indicate “TRAIN” under Vehicle Number. If you are travelling by Bus, you may input “BUS”. When the train/bus number is available, you may update your declaration via: a) "Update a Submission" if you are using the SG Arrival Card e-Service; or b) Select the submitted SG Arrival card record and tap on the "Edit" button if you are using the SG Arrival Card mobile application. https://eservices.ica.gov.sg/sgarrivalcard/