trap focus menu?

[wizbrewery]

Hi,

I'd like to use trap focus on my eos 100D to take a picture when a subject comes into focus.  I currently don't see this option in focus menu

I get:
Focus Follow
Focus Endpoint
Rack Focus
Focus Settings
DOF settings
Focus patterns

From the User Manual I can see:

'Activating AF mode dialog when Manual Focus is active will toggle Trap Focus'

How do I activate autofocus mode to see this menu option please? 
I'm using the beta build for EOS 100D BETFW1012017Jan06
thanks