iOS build - how to set iPhone-only (no Xcode) on Starter plan?

Hi, I'd like my iOS app set to iPhone-only rather than universal (targeted device family = iPhone), so it isn't offered as a native iPad app. App: Saffaroo, Bundle ID: au.com.saffaroo. It's a phone-only app, and Apple flagged an iPad-specific issue (Guideline 2.1a — Sign in with Apple spinning forever on iPad Air). I'm on the Starter plan and build in the cloud with no Mac/Xcode. Is there a way for me to set iPhone-only myself in App Studio, or can you enable it for my build so it takes effect on my next rebuild? Happy for it to run on iPad in phone-sized view.