if its a ground out let it may just need the button reset .other then that it may need to be replaced by an pro.
Check the power box for the outside plug switch, and whichever switch is not align with the others , then align it with the other switches so the they ALL are aligned in the same direction. To check for alignment, glide one of your finger along the switches for perfect alignment and correct the uneven switch. Now, check to see if the outlet outside works. If not call an electrician.
Do you mean an electrical socket or some other type of plug?
Check main breaker box make sure circut for outside plugs are not tripped to off; check on plug itself if it's GFCI rated plug that it has not flipped off push the reset on it test/reset https://www.youtube.com/watch?v=b6ilpnbWt_I ANOTHER https://www.youtube.com/watch?v=trLeLJdMWWI