How to boot from sda disk sytem installed on nvme drive? Ubuntu 20.04

I just tuned up my laptop (Dell E5250) by installing nvme m.2 drive into PCIe (WWAN) port. Ubuntu recognize drive, but bios(uefi) doesn't see nvme. Otherwise there is installed sata (sda) disk with system. I tried to install grub and boot folder on sda disk and system on nvme disk, but after start computer, there are some errors:

error: no such device:7110c-very-log-number..
error: file ~/boot/vmlinuz-5.11..... not found.
error: you need to install kernel first.

Press any key to continue...

Which files and folders shoud I install on sda drive to propper boot system? I would like to use all system from nvme drive not only /home folder. Could You help me please?

You can put /boot into a separate boot partition in a drive that is recognized at boot. Then the system will see your nvme drive and you can have your root partition / (and /home partition if you have one) in the mvme drive.

I have installed a system like that in one of my computers, and it works well for me.