Dat file size change possible?

[jls1]

Hello
I got the following errors, but the file has been resized

Code:

$ sh ExtendPersistentImg.sh /media/demo/Ventoy/persistence_ext4_512MB_MX-Persist.dat 1024
Extend dat file... (current is 512MB, append 1024MB, total 1536MB)
losetup: /dev/loop1: failed to set up loop device: Permesso negato
Extend ext filesystem by resize2fs ...
resize2fs /dev/loop1 1536M
e2fsck 1.44.5 (15-Dec-2018)
e2fsck: Permesso negato while trying to open /dev/loop1
You must have r/w access to the filesystem or be root
resize2fs 1.44.5 (15-Dec-2018)
open: Permesso negato while opening /dev/loop1
losetup: /dev/loop1: detach failed: Permesso negato

======= FAILED =========