dirmngr: 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/dirmngr - from package: dirmngr

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

On Debian possible default full paths are:

/usr/bin/dirmngr - from package: dirmngr

You may install the required package with command apt-get install {package}

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