In QGIS 3.12.2. I created a virtual layer to use for the sort-order in a print layout as described here: Sort attribute table by hidden column in Print Composer
That works, but I have a problem with the geometry. The virtual layer does not seem to have a geometry and I was not able to create one in the edit field of the virtual layer (I tried set automatically as well as defining a point-geometry and the CRS of the original layer it is created from). In the layers panel, the virtual layer shows with a point-rendering symbol, however does not show on the map. Also zooming to the layer has no effect.
Here is what I tried, based on the first link above: