Radxa Rock 5B, nvme-boot... Need some help!

Hi there,
sorry, I am new to the forum and can’t find an answer for my problem.

I have an installed DietPi 8.19 on my sd card and wanted to transfer it to a nvme drive. So i googled, tried many things, but I was not able to boot from the nvme.

First I cleaned and formated the nvme. Than I make an exact copy from the sd card to the nvme with the “dd” command (disk:mmcblk1, part:mmcblk1p1 to disk:nvme0n1, part:nvme0n1p1). After that was done, i changed on the nvme in the “/etc/fstab” the ID of the drive to the nvme one. After all I use this → Rock5/install/spi - Radxa Wiki
to flash the SPI. I also checked the md5sum of the bootloader with the file, everything seems to be fine, shutdown, pull sd card and started again.
I don’t know what to do, it is not booting. Tried so many things and read so many documentations. Is this way possible to bring a running DietPi to a nvme drive?

Am I totally wrong with my idea?

Thanks for your help!