Help with integration with Nagioscore

Hello Team,
We are integrating xmatters with nagios core as per below document
https://github.com/xmatters/xm-labs-nagios
The problem is alerts which are generated by nagios are not showing up in xmatters. Are there any steps which we can make use of to step the integration.
Do we need to install xmatters agent where nagios is running or we need to install the agent in the machines which we wanted to step alerts.