Would like to request the data source “Session Campaign” from GA4 data. Currently it is not present. It would be useful so we can connect our utm campaigns that we setup across our marketing efforts.

This is available. In the GA4 connector the Session Campaign dimension is exposed as Campaign name (id: campaign_name, under the Session Source table), which maps to GA4’s sessionCampaignName, plus Session campaign ID (id: session_campaign_id, under the Traffic Source table). It is just labeled Campaign name rather than Session Campaign, so select those fields to report on your UTM campaigns at session scope.
