How to fix APT error NO_PUBKEY B53DC80D13EDEF05

Problem:

When you run apt update, you see the following error message:

Err:12 http://packages.cloud.google.com/apt gcsfuse-bionic InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53DC80D13EDEF05

Solution

Install the Google Cloud key using

curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg| gpg -o /usr/share/keyrings/kubernetes-archive-keyring.gpg --dearmor

After that, you can try running

sudo apt update

again.