Nagios plugins PHP error

I want to set up this plugin, but it doesn’t work.
https://exchange.nagios.org/directory/Plugins/Hardware/Storage-Systems/SAN-and-NAS/Check-TeraStation-Storage/details

The plug-ins are placed here:
/opt/omd/sites/toguchi/local/lib/nagios/plugins

But, the custom check for service discovery shows an error like this image.

How can I solve this problem?