apt-get update failed because certificate verification

While trying to install Zabbix update, the certificate chain expiry error occurs. The solution is to fix by installing ca-certificates

$ sudo apt update
Hit:1 https://download.docker.com/linux/ubuntu bionic InRelease
Hit:2 http://archive.ubuntu.com/ubuntu bionic InRelease
Hit:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
Ign:4 https://repo.zabbix.com/zabbix-agent2-plugins/1/ubuntu bionic InRelease
Hit:5 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
Hit:6 http://archive.ubuntu.com/ubuntu bionic-security InRelease
Ign:7 https://repo.zabbix.com/zabbix/6.2/ubuntu bionic InRelease
Err:8 https://repo.zabbix.com/zabbix-agent2-plugins/1/ubuntu bionic Release
Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verifin. [IP: 178.128.6.101 443]
Err:9 https://repo.zabbix.com/zabbix/6.2/ubuntu bionic Release
Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verifin. [IP: 178.128.6.101 443]
Reading package lists… Done
E: The repository ‘https://repo.zabbix.com/zabbix-agent2-plugins/1/ubuntu bionic Release’ does not have a Release file.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository ‘https://repo.zabbix.com/zabbix/6.2/ubuntu bionic Release’ does not have a Release file.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

$ sudo apt install ca-certificates
[sudo] password for devopsadmin:
Reading package lists… Done
Building dependency tree
Reading state information… Done
ca-certificates is already the newest version (20211016~18.04.1).
The following packages were automatically installed and are no longer required:
linux-headers-4.15.0-112 linux-headers-4.15.0-112-generic linux-headers-4.15.0-74 linux-headers-4.15.0-74-generic linux-image-4.15.0-112-generic
linux-image-4.15.0-74-generic linux-modules-4.15.0-112-generic linux-modules-4.15.0-74-generic linux-modules-extra-4.15.0-112-generic
linux-modules-extra-4.15.0-74-generic
Use ‘sudo apt autoremove’ to remove them.
0 upgraded, 0 newly installed, 0 to remove and 130 not upgraded.

$ sudo apt update
Hit:1 https://download.docker.com/linux/ubuntu bionic InRelease
Hit:2 http://archive.ubuntu.com/ubuntu bionic InRelease
Get:3 https://repo.zabbix.com/zabbix-agent2-plugins/1/ubuntu bionic InRelease [4,948 B]
Get:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
Get:5 https://repo.zabbix.com/zabbix/6.2/ubuntu bionic InRelease [7,125 B]
Get:6 https://repo.zabbix.com/zabbix-agent2-plugins/1/ubuntu bionic/main Sources [660 B]
Get:7 https://repo.zabbix.com/zabbix-agent2-plugins/1/ubuntu bionic/main amd64 Packages [475 B]
Get:8 http://archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]
Get:9 https://repo.zabbix.com/zabbix/6.2/ubuntu bionic/main Sources [1,152 B]
Get:10 http://archive.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]
Get:11 https://repo.zabbix.com/zabbix/6.2/ubuntu bionic/main amd64 Packages [3,908 B]
Fetched 270 kB in 3s (89.5 kB/s)
Reading package lists… Done
Building dependency tree
Reading state information… Done
131 packages can be upgraded. Run ‘apt list –upgradable’ to see them.