Thanks.
It works.
I have installed it manually.
/usr/share/doc/x11-driver-video-nvidia-long-lived/README.manual-setup
[root@localhost mila]# uname -a
Linux localhost.localdomain 4.19.6-desktop-1omv #1 SMP Mon Dec 3 10:45:49 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost mila]# dkms status | grep nvidia
nvidia-long-lived, 390.87-1, 4.19.6-desktop-1omv, x86_64: installed
I needed to add nokmsboot parameter into my grub.
By https://wiki.openmandriva.org/en/3.03/Errata#Black_Screen_at_Boot