Remote Icinga instance 'Firewall' is not connected to 'icinga1'

Hello Everyone,I am new to linux as well as to director.
I am adding network devices for eg. firewall for now . I configured the host and services set so the device is reachable and also ping test is up.
And i have configured the nw_health check plugin for the firewall,But I donot see where to check for the details from icinga,now it just shows that the firewall is UP but I need more information.
And also I am getting this error in the services tab " Remote Icinga instance ‘Firewall’ is not connected to ‘icinga1’ "
Can someone please help me with how to move forward with this task.