It has been noticed that some time buyer did not send the exact requirements and send wrong information but Fiverr starts the countdown how to overcome this problem.
You need to try and get message the buyer, and let them know you need the information required.
Cancelling, the order affects your completion rate.
You can also ask him to agree to extend delivery, so that he can submit the required info, but sometimes when you do that, and they don’t respond before the order is due- you are late, and/or forced to cancel- which also affects your cancellation rate, in addition to your completion rate.
I would complete the order with the information you have, and hand it in - if you can’t get a hold of him or her. If he/she asks for a revision - you can do that, it won’t affect completions. cancellations etc, because your initial delivery was on time.
Your countdown has started… it cannot be stopped. If you feel that the buyer did not provide the kind of information that you need, then send a message to the buyer and ask them for the right information.
I understand your reply, but my question is that why Fiverr not understand this issue because some buyer not understand the requirements and Fiverr starts countdown.
Fiverr countdown has been started because it has been done by coding. They will not check everything Manually and after that they start. If you need more information about project you can ask to your buyer and If you need more time you can extend time duration as well.