R6 Mark ii - No custom functions (like C.Fn1) appear in the Custom Functions menu

[gladivs]

I want to set a Custom Function on my R6 Mark ii but none of the 5 possible functions are listed in the Custom Function section.  Any suggestions?  Ultimately I'm trying to the R6 to leave the display blank except when I go into the menu or when I playback a photo.  I read this is a place to do that.  Screen/viewfinder display is set to AUTO2.  I don't use the display to frame a shot, I use the viewfinder.  

[kvbarkley]

You might need to be in a creative mode like P

[p4pictures]

Kevin is right that custom functions menu is not shown unless the camera is set to a creative mode such as P, Tv, Av, M, Fv. 

What is displayed on the rear screen is determined by pressing the INFO button while the LCD screen is showing. There are five possible displays, but unlike EOS R5, R5 Mk2, R3 & R1 you cannot have a blank display as one of the options. To achieve something similar set tbe camera to display on the LCD where you currently have AUTO2 selected, and then reverse the lcd so it is closed and not visible. The camera will now only use the viewfinder, but when you open the lcd the menus and screens will show only on the LCD.