No Bootrunner Screen

A friendly hello

I need help.
After updating iMac os 10.14. after 10.15.6 macOS Catalina
Reinst. Bootrunner 3.2 including inserting Reg.Key, and creation
One profile, no bootrunner start screen.
Selection of the landing stage only via alt. Button possible
What do I have to do.
The Command
csrutil enable --without nvram,
Didn’t get me any further either.

Regard. A. Nickel

Is it possible it is logging in to the user? Boot Runner will show over the login window but if you are using File Vault, the user is automatically logged in.