Error apt-get update

i’m getting error for apt-get update

here is the message

“W: Some index files failed to download. They have been ignored, or old ones used instead.
W: Not using locking for read only lock file /var/lib/dpkg/lock”

i have commands “sudo mount -o remount,rw /”

but it’s still not working

can u help me ??

@Azizal_Yunan_P
We use a read-only root file system managed by OSTree with application installed using Flatpak