Is it possible to activate integrated calling on an Android phone?

"RingCentral calls will be interrupted by incoming mobile calls when Integrated Calling is disabled. "

Check here how to manage integrated calling:

https://support.ringcentral.com/article/10693-RingCentral-Phone-Mobile-App-Managing-Integrated-Calling.html

and here

That article shows an app that looks different from the one we're using. There is no option for activating integrated calling on Android or iOS.

The attached screenshot shows what options I've got when I scroll to the bottom as you suggest. There is no option for turning on integrated calling. So far I'm really not enjoying the RingCentral mobile app!Screenshot_20201222-103429.png