DiscoveryAgentJobs doesnt work

[qlync]

hello everyone! zabbix cant get value from veeam server. In discovery rules, status DiscoveryAgentJobs = "Value a should be a JSON object".
When im trying in zabbix server cli:
zabbix_get -s HOST -k 'vbr["DiscoveryAgentJobs"]'
i get: -- ERROR -- : Need an option !
other discovery methods works fine.
please, help me)