Add free Google Shopping listings/hits as a channel

Hello to all,
Has anyone experience with defining the free Google Shopping hits as their own source? In the URL, the people who come in via Google Shopping at least have their own referrer ID. If we could exclude from this total the amount that come in through the paid Google Shopping ads, we would have the amount that we want to have. Unfortunately, we are still quite new on Matomo and still no experience how to implement something like this. Has anyone ideas or tips on how to implement?

Kind regards
Stefanie