Install Root CA as Trusted CA on the Hosts

Ubuntu

Copy crt file to /usr/local/share/ca-certificates, Run command sudo update-ca- certificates.

CentOS

Copy crt file to /etc/pki/ca-trust/source/anchors, Run command sudo update-ca- trust extract.

Windows

Double click the file and add the cert to Trusted Root, or Run command certutil -addstore "Root" <crt-file>.