Windows server 2019 install not showing GUI options
Solution 1:
These days Windows server comes not only in different editions but also in different types:
Long-Term Servicing Channel - This is usually the initial release of a server, and it gets monthly security updates, but no new features. It also can not be freely upgraded to a newer version of the server as is the case for Windows 10 clients.
The current version is Windows Server 2019 - 1809
This version has both Server Core and full server (desktop experience).
Semi-Annual Channel
This has two releases each year, in 2019 it had versions 1903 and 1909
This type only comes with Core editions, no desktop experience. If you want a desktop you have to use the last Long-Term Servicing Channel
version.
It seems you downloaded 1909 which is the latest Semi-Annual Channel
and has no Desktop option.
Solution 2:
On some Windows 2019 editions, the GUI is installed by default. You can simply select "Windows server standard".