ots: 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/ots - from package: libots0

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

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