[FIXED] Proxmox VE 5.4 Failed to update

I recently updated my proxmox VE 5. Running an "apt update" produced this error:

Err:5 https://packages.sury.org/php stretch InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B188E2B695BD4743
Hit:6 http://download.proxmox.com/debian/pve stretch InRelease
Reading package lists... Done
W: GPG error: https://packages.sury.org/php stretch InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B188E2B695BD4743
E: The repository 'https://packages.sury.org/php stretch InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.

The solution would be is to download a new key from the repository. DPA has a new signing key that causes this error

wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg

After download, run the apt update again ang everything will work now.