Kibana link to text file. (kibana:7.6.2)

Hi experts,
We are trying to display a link inside a Kibana document; when a Kibana user click on that link, we want a new tab to display a text file. Right now, we have simply put the text files inside the bundles folder (/usr/share/kibana/optimize/bundles/text_files/) and make that field a url that point to this location. The problem is that anyone not login inside Kibana can now access and visualise those text files (e.g We were wondering if there is a way to serve and protect static content with the Kibana authentication mechanism.

Thank you.