AirPods control screen different from what appears on Support page - can't change press-and-hold settings.

When I first started using my AirPods Pro - 2 weeks ago - press-and-hold toggled on/off noise-cancelling. Now it summons Siri instead (and Siri is next to useless for me, so that's not good). This article describes how to change the press-and-hold setting, but the screen looks different on my iPhone and shows no press-and-hold adjustment capability. Is this all because I'm still on an iPhone 6, which can't be upgraded to iOS14?