According to the detox docs: https://github.com/wix/Detox/blob/master/docs/APIRef.DeviceObjectAPI.md going back is Android only. What would be the recommended way of going back with IOS?
As with any interface element, you should set an identifier to the back button and then tap on it in your test.
The back function in Android simulates the physical back button, which is not available on iOS.