Hi @claudiu,
Welcome to the Forum, and thank you for posting your question here.
First, you should set up an incoming configuration and a webhook in Alumio that will process the webhook requests. You can follow this documentation on How to access data send to an Alumio webhook?.
You will then have the URL of the webhook in the page of the newly created webhook.
In the Elasticsearch watcher, you can use the webhook URL to send your data to Alumio.
Please give it a try and let us know if you find any issue.