Is it require to get an electrical inspection?

If the home is in the country (not inside a city limit) then in most cases, no inspection is required. However, it is the electrician’s responsibility to request an inspection when ever he completes his rough-in wiring. If he did not do this, he is either not an electrical contractor and is not licensed to call in an inspection, the home is located in an area where an inspection is not required or he just forgot. Contact the electrician and ask why he chose to not call in an inspection.
BTW: Electrical inspectors will very rarely require sheetrock to be removed because of no inspection. Any inspector worth his salt can inspect a wiring installation without seeing open walls. There are mistakes and mis-communications made by both contractors and inspectors alike. Most sheetrock contractors know to look for the rough-in inspection sticker located on the inside of the panel before starting their work. Inspectors will consider the past work of an electrical contractor and the see-able wiring to make his inspection judgement.

Electrical installations in a new house must be inspected and authorized prior to connection to the Utility electricity distribution system

You must be very careful with the fact that whenever you are making a new home, the electrical installation must be got inspected and authorized prior to the connection to the Utility electrical distribution system for avoiding any kind of problems in the future.