kdeconnect-cli: 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/kdeconnect-cli - from package: kdeconnect

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

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