Node-Red write to file not working

[Castorp]

Hello.

I'm absolutely new to GC and my experience with VM, Linux etc is bad at all.

But I managed to order a VM with Node-Red preinstalled by Docker and access it.

I set up my Flow and everything works fine. Now I would like to have a Node write some output to a file but the path I enter is not working. I assume I made some mistakes by ordering/configuring the VM, so maybe there is no Linux installed. The only directory I see is /home/"my_username", but Node-Red don't make a file there. Can anybody tell me what I made wrong and how to fix it? The only goal I have is to write Node output into a file.

Thanks for your help in advance.

BR