Harddrive replace in a MyCloud HOME (not DUO!)

I want to replace the hard drive in my MyCloud HOME. I already tried it. It was even automatically formatted 1: 1 as the original disk.

My way:
Power off. Built-in HDD. Press reset and power plug in on the same time. Then the LED flashes quickly. Power off. Power on again. After that, the hard drive was just formatted like the original hard drive. With 23 Partitions and so on.

The problem is now the 9-digit code in the reinstallation apparently no longer work. It will not be recognized as a new MyCloud HOME. What can I do?

This is a screeshot from the formatted harddrive in the MyCloud HOME:

The My Cloud Home single bay drive are not field serviceable. IE: if the HDD fails, RMA the entire enclosure including the drive.

“The My Cloud Home single bay drive are not field serviceable.”
This is not particularly customer friendly :frowning:

What about the HOME DUO?
I read that the user can change the hard disks themselves on this device.
Can I just buy my hard drives free on the market for this? Or do I have to order special hard drives from WD especially for my MyCloud HOME DUO?