OpenAtlas

GeoJSON is very good to use in web environments. Although QGIS can read GeoJSON, it cannot really handle it well, and it needs to be transferred. Since this require a manual task, it was requested, if the resulted geometries can be downloaded as
.gpkg.

I looked already into it, there is a promising package for this: python3-fiona (GitHub)

Implementation
Added new gpkg to the format parameter. It just uses the geojson-v2 and generates a download of a gpkg.