Can't add external storage

hello, i have RP3 with ubuntu 16.04.4 on it, running nextcloud snap version.

i have 16gb of usb that i want to mount but can’t get it working
i did the following:

sudo mount -t ntfs-3g /dev/sda1 /media/disk001
sudo chmod -R 0770 /media/disk001

in /etc/fstab i added:
UUID=xxxxxxx /media/disk001 auto nofail,uid=1000,gid=1000,noatime 0 0

in the admin panel i did the following:

now i have folder called ‘disk001’ and when i try to add something in the folder i get ‘Internal Server Error’

can someone help me with this problem?, thanks

update: after playing with it, now when i upload something i get the following message ‘Forbidden’

maybe you should use sudo chown www-data:www-data -R … ?