Platform and Runtime tags are not populated

I’m using sentry both in Node and React, I want to have just one project and filter events from front-end or back-end, but I cannot seem to find how, in search I see there are two tags (Platform and Runtime) but both are empty, should they be empty? is there a way to populate those tags? is there any other way to filter which events are coming from back-end and which from front-end?