need php module "bcmath"

Code:

IspConfig3.1.15p3/VPS/Debian10/PHP 7.4.16 (cli)

Hi guys ;
I need this module "bcmath" and I tryed by console "apt-get update" and I have errors :

Code:

/var/www/clients/client0/web2/web/wp-content# apt-get update
Hit:1 http://security.debian.org buster/updates InRelease
Hit:2 http://deb.debian.org/debian buster InRelease                                                                                                                               
Hit:3 http://deb.debian.org/debian buster-updates InRelease                                                                                                                       
Hit:4 http://deb.debian.org/debian buster-backports InRelease                                                                                                                     
Hit:5 http://security.debian.org/debian-security buster/updates InRelease                                                                                                         
Hit:6 http://ppa.launchpad.net/scaleway/stable/ubuntu bionic InRelease                                                                                                           
Get:7 https://packages.sury.org/php buster InRelease [6,837 B]                                                                                                                   
Err:7 https://packages.sury.org/php buster InRelease           
  The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key <[email protected]>
Reading package lists... Done
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list:13 and /etc/apt/sources.list:33
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Translations (main/i18n/Translation-en_US.UTF-8) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packages.sury.org/php buster InRelease: The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key <[email protected]>
W: Failed to fetch https://packages.sury.org/php/dists/buster/InRelease  The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key <[email protected]>
W: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list:13 and /etc/apt/sources.list:33
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
W: Target Translations (main/i18n/Translation-en_US.UTF-8) is configured multiple times in /etc/apt/sources.list:12 and /etc/apt/sources.list:32
root@srv-b:/var/www/clients/client0/web2/web/wp-content# 

Is it the good way or do I need update debian packages from ispConfig interface ?
And is it safe now to upgrade my ispConfig to the last version ?

Tanks for your Help

 

Thanks Jesse