1. Run command line as Administrator and run command for your version of OS:
Windows Server 2016
dism /online /set-edition:ServerDatacenter /productkey:CB7KF-BWN84-R7R2Y-793K2-8XDDG /accepteula
Windows Server 2019
dism /online /set-edition:ServerDatacenter /productkey:WMDGN-G9PQG-XVVXX-R3X43-63DFG /accepteula
Windows Server 2022
dism /online /set-edition:ServerDatacenter /productkey:WX4NM-KYWYW-QJJR4-XV3QB-6VM33 /accepteula
Wait when process ends.
2. Restart.