HVM (Ubuntu24.04) Upgradation Error: signatures couldn't be verified because the public ke

[Qzattitude]

I have downloaded the lates HVM (HPE VM Essential).

While installing HVM OS, on updating OS it hung.

From OS

root@vme:~# apt update
Ign:1 https://update1.linux.hpe.com/repo/hpevme/zion-private-ubuntu pulp InRelease
Ign:2 https://update1.linux.hpe.com/repo/hpevme/zion-os-updates-prod/ubuntu2404-os-updates noble-updates InRelease
Hit:3 https://update1.linux.hpe.com/repo/hpevme/zion-private-ubuntu pulp Release
Hit:4 https://update1.linux.hpe.com/repo/hpevme/zion-os-updates-prod/ubuntu2404-os-updates noble-updates Release
Get:5 https://update1.linux.hpe.com/repo/hpevme/zion-private-ubuntu pulp Release.gpg [833 B]
Ign:5 https://update1.linux.hpe.com/repo/hpevme/zion-private-ubuntu pulp Release.gpg
Get:6 https://update1.linux.hpe.com/repo/hpevme/zion-os-updates-prod/ubuntu2404-os-updates noble-updates Release.gpg [833 B]
Ign:6 https://update1.linux.hpe.com/repo/hpevme/zion-os-updates-prod/ubuntu2404-os-updates noble-updates Release.gpg
Fetched 1666 B in 4s (420 B/s)
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
137 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: GPG error: https://update1.linux.hpe.com/repo/hpevme/zion-private-ubuntu pulp Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6846363ABCCF9B07
W: GPG error: https://update1.linux.hpe.com/repo/hpevme/zion-os-updates-prod/ubuntu2404-os-updates noble-updates Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6846363ABCCF9B07
N: Missing Signed-By in the sources.list(5) entry for 'https://update1.linux.hpe.com/repo/hpevme/zion-private-ubuntu'
N: Missing Signed-By in the sources.list(5) entry for 'https://update1.linux.hpe.com/repo/hpevme/zion-os-updates-prod/ubuntu2404-os-updates'