NAS326 & ipcam

I purchased the new nas326 (Firmware version: V5.21AAZF.8) and I want to use it to save images captured by an ipcam via ftp protocol as I did with the old NAS. I created a user (e.g. ipcam) and associated it with a folder (IPCAM) on which it has full rights. If I run the tests I get the error 553, that is, it is impossible to write files to the root directory, as well as create subfolders.

What do you recommend?

#NAS_July_2020