This type of visa is only applicable for passengers who are passing through UAE airports. Before you make a visit to the UAE, you are required to apply for and obtain a Dubai transit visa. You can apply through UAE-based airlines and online services offered by forever tourism. You must keep in mind that 48 hours Dubai transit visa cannot be renewed or extended. It is valid for 48 hours. You must exit from the entire emirate within 48 hours. You must also understand all the necessary requirements and costs of a UAE transit visa for 48 hours.
Yes, off course you can book the tickets to Dubai before processing or applying of visa.