update-ca-trust: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/update-ca-trust - from package: ca-certificates

You may install the required package with command yum install {package}

psssst... Do you have issue with CA root certificates on your system? Is it a DirectAdmin server? check out this post: DirectAdmin x509: certificate has expired

Error in other languages:
update-ca-trust: bevel nie gevind nie
update-ca-trust: comandă negăsită
update-ca-trust: comando não encontrado
update-ca-trust: commande introuvable
update-ca-trust: command not found
update-ca-trust: käsku ei ole
update-ca-trust: không tìm thấy lệnh
update-ca-trust: komanda nerasta
update-ca-trust: Kommando nicht gefunden.
update-ca-trust: kommandot finns inte
update-ca-trust: komut yok
update-ca-trust: nie znaleziono polecenia
update-ca-trust: níor aimsíodh an t-ordú
update-ca-trust: no se encontró la orden
update-ca-trust: no s'ha trobat l'ordre
update-ca-trust: opdracht niet gevonden
update-ca-trust: parancs nem található
update-ca-trust: perintah tidak ditemukan
update-ca-trust: príkaz nenájdený
update-ca-trust: příkaz nenalezen
update-ca-trust: команда не найдена
update-ca-trust: командата не е открита
update-ca-trust: 命令找不到
update-ca-trust: コマンドが見つかりません