Copy script check_backup.ps1 in NSClient++ scripts folder on Windows Server Client
Edit NSC.ini (config file for NSclient++) and add in section [External Scripts]
check_backup=cmd /c echo scripts\check_backup.ps1; exit($LastExitCode) | powershell.exe -command -
Authorize remote scripts execution
In powershell (Run as Admin) execute this command
Set-ExecutionPolicy remotesigned
Restart service NSClient++
On powershell
Restart-Service NSClientpp
Enable feature .NET Framework
DISM /Online /Enable-Feature /FeatureName:NetFx3