Problem on Unity export

Hi,
i am a french student in high who will do an intern ship in a company which works on Hololens (excuse for my english, i could write some mistkakes sometime). I follow this microsoft turoial : https://developer.microsoft.com/en-us/windows/mixed-reality/holograms_101e and i am blocked at the first step, i don't arrive to export my unity project to try it in the hololens emulator on Visual Studio. Unity saies to me that there is a problem in the compliator. Do you solutions ?

Thank you,
Pierre-louis