Installing new programs on Debian for Rock Pi 4

How do I do it? In other forms of Debian you use Synaptic. There doesn’t seem to be an equivalent Graphical Package Manager in the image Radxa offers. Whadup?

On Armbian desktop synaptic works as expected.

That would be great if the Armbian image available on this site did anything. I put it in, turn it on and nothing happens unlike all the other images, viable or not.

Perhaps using official builds for start? -> download