I have been to Coz twice since the required COVID test to return. I used the Verifly app both times. The app is poorly written and requires plenty of trial and error to use correctly. We had printed results just in case, but we got right into check-in line just flashing the info from our phone.
Obviously the second trip was much easier, since the app was already installed and basic info stored. We got tested at CostaMed and had the antigen test results back in about an hour. Screen capture the document, drag and drop into Verifly.