Hi!
You can deploy Wazuh to an already existing Elasticsearch or OpenSearch stack, you just need to install the Wazuh plugin in Kibana like this:
You will need to configure Filebeat on the Wazuh manager side to send the alerts to your elastic stack, here you have a guide on how to configure Filebeat:
https://documentation.wazuh.com/current/deployment-options/elastic-stack/distributed-deployment/wazuh-cluster/wazuh-single-node-cluster.html#installing-filebeat