Hi @Aysha,
without exactly knowing what you put into the Artifact, the only guess I can take is based on this line in the log
2023-08-04 09:54:22 +0000 UTC error: transient error: Reboot to the new update failed. Expected “upgrade_available” flag to be true but it was false. Either the switch to the new partition was unsuccessful, or the bootloader rolled back
So it seems that whatever is in that container.tar.gz that you tried to install is not properly handled. Even more guessing: it is not a full root filesystem, as you are talking about containers.
mender-artifact write rootfs-image
is meant for full system deployments. To create an Artifact for the docker Update Module, use the matching generator script, as mentioned in the already linked tutorial.
Greetz,
Josef