openpgpkey: 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/openpgpkey - from package: hash-slinger

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

On Debian possible default full paths are:

/usr/bin/openpgpkey - from package: hash-slinger

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

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