Create key:
sudo openssl req -new -x509 \
-newkey rsa:2048 -keyout /var/lib/dkms/dkms-mo.key \
-outform DER -out /var/lib/dkms/dkms-mo.der \
-nodes -days 36500 -subj "/CN=Driver dkms Signing MOK"
Enroll key:
sudo mokutil --import /var/lib/dkms/dkms-mo.der