score:2
You can stay in the airport transit area without a transit visa. There are airside hotels, so you do not necessarily need a visa at all. But if you want to pass immigration and enter Dubai, you can use this process:
Since you booked your flight with flydubai, you can apply for the 96-hour transit visa which lets you leave the airport and enter Dubai. You can do this at any of flydubai's travel shops. There are travel shops in Istanbul and Sialkot (so you can also get one if you leave again) and most other cities which flydubai serves. I cannot tell what, if anything, the charge is for the visa.
Unfortunately flydubai does not have a process to apply for the transit visa online, as Emirates and Etihad do.
This visa can only be obtained in advance, not on arrival.