repmgrd: 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 Debian possible default full paths are:

/usr/bin/repmgrd - from package: repmgr

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

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