Lab 4.2 Error while running bash -x ./slave_nfs_node.sh <anod-master VM internal IP>

Though the script runs, but I see these errors.

Err:5 https://packages.cloud.google.com/apt cloud-sdk InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FE EA9169307EA071 NO_PUBKEY 8B57C5C2836F4BEB
Fetched 4057 kB in 1s (4324 kB/s)
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previou s index files will be used. GPG error: https://packages.cloud.google.com/apt cloud-sdk InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FEEA916 9307EA071 NO_PUBKEY 8B57C5C2836F4BEB
W: Failed to fetch https://packages.cloud.google.com/apt/dists/cloud-sdk/InRelease The following sig natures couldn't be verified because the public key is not available: NO_PUBKEY FEEA9169307EA071 NO_P UBKEY 8B57C5C2836F4BEB

Can these be ignored?