Cannot edit NAS folder contents from the Mac Finder remotely

Hello.
I have a problem with the remote access of MyCloudEX2Ultra on Mac. I have connected it correctly and I see it in the Finder, and I can even access it. The problem is that I can only view the contents, without being able to edit them. Everything is enabled from the control panel on the NAS. From Windows, however, I can perfectly make changes.
If I click “Get information” and in “Shares and permissions” I try to select “read and write” I get the following error “I cannot complete the operation because you do not have the necessary privileges.”
How can I solve?
Thank you

@frasca

Who is the administrator? By the way, you are posting in the wrong sub-forum. This is for the WDMYCLOUD.
WDMyCloudImage

@cat0w I am the sole administrator of the Mac.