FP4 with ubuntu touch connected to a PC

Help Fairphone 4
,
1

A question to ubuntu touch users:

I am trying out the newest ubuntu touch version on Fariphone 4. But when connected with a suitable cable to a PC it is absolute impossible to write a new folder or a file on it. How to unlock it?

Thanks for a hint, because if this is not possIble, then this OS is simply useless.

2

Update: I just realized (with trial and error…) that apparently the top folder structure is fixed but it is possible to make subfolders (Unterordner), a bit funny, but I will get used to it.