It is the document for using ELK as an on-premise analytics solution for WSO2 API Manager 4.0.0.
https://apim.docs.wso2.com/en/latest/api-analytics/on-prem/elk-installation-guide/
But I don't know how to use Zabbix instead of ELK.
WSO2 API Manager 4.0.0 supports ELK as an on-premise analytics solution by default. You can write a connector for a analytics solution of your choice (Zabbix in your case). For this, please follow this documentation.