Hello,

the error message is something along the lines of: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key <deb@sury.org>

How to fix? Pretty easy, get the new key for the Sury repo:

apt-key del B188E2B695BD4743
curl -sSL -o /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg
apt-get update

After that all should be fine again!