External Storage Permissions

On My next cloud I can see the drive But it will not let me add SYNC or just add a folder just says cannot create folder and when I use the desktop app to SYNC a folder I get 403 forbidden to PUT

root@DietPi:~# ls -la /mnt/Storage/
total 24
drwxr-xr-x 3 root root 4096 Sep 16 18:44 .
drwxr-xr-x 7 root root 4096 Sep 16 18:44 …
drwx------ 2 root root 16384 Sep 16 18:44 lost+found

What file system format your external disk has? At the moment it is writable for user root only.