Setup → Settings → Tool Preferences has two related settings, both following the same pattern:
Primary HR System — which connected HR integration ComplyJet treats as the source of truth for importing employees.
Primary Background Check Provider — which connected screening integration ComplyJet syncs background-check results from.
Connect the integration first
Both dropdowns are empty until you've actually connected a matching integration under Setup → Integrations — you'll see a note like "No HR system is connected yet" until then. The dropdown only lets you pick from what's already connected; it doesn't connect anything itself.
Why "primary" matters if you have more than one
You can connect multiple HR systems or background-check providers if your company genuinely uses more than one. But only the one nominated as primary actually writes status back to your People roster — the others stay connected without feeding that data through. If background-check statuses (or employee records) aren't updating the way you expect, check that the tool you're actually using is the one set as primary here, not just connected.