Error NP-37637-6 when trying to restore to factory settings?

Hey, how are you guys?

Im trying to restore my PS4 to factory settings.

I go to the Initialise menu and initialise the PS4.

I click on FULL, it asks me if I want to deactivate the PS4 for primary accounts and I accept.

Then the spinning wheel turns a few times and I get this error message :
NP-37637-6.

It says I need to allow an internet connection. So I did that and tested the connection but it fails to connect to the PS4 Network for the test and when I retry the Initializing process I get the error again.

Now, is there a way to reset the PS4 to factory settings without being connected to the internet?

Why does it need an internet connection for a reset in the forst place?

Thanks in advance!