capi4hylafaxconfig: command not found

Have You tried accessing the binary with the full path?

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/sbin/capi4hylafaxconfig - from package: capi4hylafax

You may install the required package with command apt-get install {package}
Error in other languages:
capi4hylafaxconfig: bevel nie gevind nie
capi4hylafaxconfig: comandă negăsită
capi4hylafaxconfig: comando não encontrado
capi4hylafaxconfig: commande introuvable
capi4hylafaxconfig: command not found
capi4hylafaxconfig: käsku ei ole
capi4hylafaxconfig: không tìm thấy lệnh
capi4hylafaxconfig: komanda nerasta
capi4hylafaxconfig: Kommando nicht gefunden.
capi4hylafaxconfig: kommandot finns inte
capi4hylafaxconfig: komut yok
capi4hylafaxconfig: nie znaleziono polecenia
capi4hylafaxconfig: níor aimsíodh an t-ordú
capi4hylafaxconfig: no se encontró la orden
capi4hylafaxconfig: no s'ha trobat l'ordre
capi4hylafaxconfig: opdracht niet gevonden
capi4hylafaxconfig: parancs nem található
capi4hylafaxconfig: perintah tidak ditemukan
capi4hylafaxconfig: príkaz nenájdený
capi4hylafaxconfig: příkaz nenalezen
capi4hylafaxconfig: команда не найдена
capi4hylafaxconfig: командата не е открита
capi4hylafaxconfig: 命令找不到
capi4hylafaxconfig: コマンドが見つかりません