It all depends on the server.
But if you have a ProLiant HP iLO4
The pic might help.
In right hand corner there is option of UID click in front of it and UID will be turned on
Hello,
In the ILO Interface if you look in the bottom right hand corner of the screen you will see beside the power indicator a button that is the UID indicator that you can click to tuen it on and off.
This is with the ILO4 and lates FW but im sure from meeory tis always been there.
Hope this helps someone !