BrailleNote Apex how to switch between Nav on/off?

Braille on Apple Products

Using a BrailleNote Apex as a Braille display and keyboard on an iPhone 5S, what's the command to quickly switch between Nav modes, like on a qwerty keyboard one does with I think left&Right arrows together? On the website of

which I use as a quick reference, I can't seem to find the command.