windows server 2012/16/19 upgrade

i all ,

I am facing troubles while doing the upgrade from windows server 2016 Evaluation standard to Windows server 2019 Evaluation Standard .
I can do a clean upgrade ,wiping out the personal files and apps , but I need to keep those files and apps . However I can't choose the second option . Only erasing all file is available .

Same thing happens when I try to do upgrade from Windows server 2012 R2 to server 2016 or 2019 !!

What might be the problem ? Do I have to get a full licensed windows to be able to do such upgrade !

Any help or a hints are appreciated .

Thank you in advance