during boot, after the grub screen there appears shortly the following message on the screen:
can it be ignored, or does it point to a problem?
secure boot is activated
Do you notice any issues?
no, I didn’t notice any that I would attribute to a missing certificate - what doen’t mean a thing 
What would I do? I’d check for a BIOS update. We use the Discover app to check for any BIOS updates, and if available, it’ll install it.
I don’t know how Discover on opensuse can detect a BIOS update, but I just did a BIOS update from within windows.
Not sure what “Windows” is 
I have the options set to On within Discover to check for BIOS updates:
.
.
I wonder whether the missing certificate message is caused by nvidia drivers whose certificates have not been enrolled to MOK.
I tried
mokutil --list-enrolled
but this reults in
EFI variables are not supported on this system
Further, I didn’t find any nvidia pubkey in the system.
How can I check whether nvidia drivers cause the message, and if so: how can I enroll the pubkey to MOK?
rpm -qa GI nvidia
nvidia-open-driver-G06-signed-kmp-default-550.144.03_k6.4.0_150600.21-150600.3.29.2.x86_64
nvidia-compute-utils-G06-550.144.03-lp156.30.1.x86_64
kernel-firmware-nvidia-gspx-G06-550.144.03-lp156.74.1.x86_64
kernel-firmware-nvidia-20250122-150600.3.12.3.noarch
nvidia-settings-570.124.04-lp156.32.1.x86_64
nvidia-gl-G06-550.144.03-lp156.30.1.x86_64
openSUSE-repos-Leap-NVIDIA-20250303.f74564e-lp156.2.6.1.x86_64
nvidia-video-G06-550.144.03-lp156.30.1.x86_64
nvidia-compute-G06-550.144.03-lp156.30.1.x86_64
nvidia-libXNVCtrl-570.124.04-lp156.32.1.x86_64
nvidia-video-G06-32bit-550.144.03-lp156.30.1.x86_64
nvidia-compute-G06-32bit-550.144.03-lp156.30.1.x86_64
nvidia-drivers-G06-550.144.03-lp156.30.1.x86_64
nvidia-utils-G06-550.144.03-lp156.30.1.x86_64
nvidia-gl-G06-32bit-550.144.03-lp156.30.1.x86_64
mokutil --list-enrolled is working …
I had overlocked that: