Not working without serial connection

[svake]

Hi,

I'M still a rookie with all the stuff. I want to use the menu on a ESP32C3 via Arduino with only one button. The chip is battery driven and won't have a serial connection. Problem is that I can't operate the menu without a serial connection. The menu is working only after establishing a serial connection. I use nav.doNav(xxxCmd); with short and long press for navigation which works quite well.
For the Navroot I tried NAVROOT(nav,mainMenu,MAX_DEPTH,NO_INPUTS_NAV,out); with macros.h. NO_INPUTS_NAV was originally commented out in macros.h. Anyway, this way generates just errors.
In the .ino file I removed already everything which has to do with serial without success.
I'm quite sure there is an easy way to just use the menu without any serial connection, I'm just not able to find it. Help is highly apreciated.

[svake]

Okay, I found it myself. I testet this solution already, but at that time there where errors. I used
chainStream<0> in(NULL);
NAVROOT(nav, mainMenu, MAX_DEPTH, in, out);
and now it works fine without serial connexion.
Another question: Is there a simple way to use an inverse text for the active row instead of the prompt with u8x8?