Hi. Are you asking for a programatic way to import the geometry JSON into ArcGIS Pro, or for a tool in ArcGIS Pro to read the geometry JSON? If the former, I think this question belongs in the ArcGIS Pro SDK place.
Programatically, perhaps start here.
It also looks like there's a JSON Import tool in ArcGIS Pro. See here.
But note that geometry.tojson() will only output the JSON for the geometry object, not a full feature. The ArcGIS Pro links above require full Featureset JSON - see here. You may need to process your geometry JSON into that format to import it.