Hum… Okay, I didn't have access to our Dell Digital Locker (it was just empty); but since I got access to this, I could get back the license! Great. It's solved then 
Hi, I've got an iDRAC really stuck and I had to reset it. Good surprise, the iDRAC is back ! Bad surprise : the perpetual license is lost since reset. In OME, I still have a line for iDRAC8 Enterprise License but only with a "right ID". But this iDRAC is locked in Express version now! How can I please recover the iDRAC8 Enterprise License for this PowerEdge R630? And how could I do to automatically retrieve all Dell PowerEdge iDRAC Enterprise License we have and store it? The Dell support didn't reply me at this time … Thanks !
iDRAC8 Enterprise License lost at reset