Firstly the zabbix agent running on the server must be allowed to execute remote commands, so update your zabbix_agentd.conf by setting

EnableRemoteCommands=1

Restart zabbix agent.

Then you can create an item of type “Zabbix agent”, type of information “Text” and with following expression:

system.run["systemctl is-active myservice.service"]

Now create a trigger from this Item. Add the following Expression and change the hostname to yours

{host1.example.org:system.run["systemctl is-active gobgpd.service"].iregexp(inactive)}=1

If using a template trigger, replace the host with template name:

{Role bgp host:system.run["systemctl is-active myservice.service"].iregexp(inactive)}=1