Hi nsirot,
Can you tell me if you are using Open Distro for Elasticsearch (ODFE) or x-pack? To know if you are using x-pack you can look at /usr/share/kibana/plugins/
Depending on one or the other, a more restrictive access can be specified. In the case of ODFE, it cannot be configured to access or not certain sections, but the actions to be carried out can be limited in such a way that it is not allowed to create or modify (an error message appears informing that there are no permissions).
If it is x-pack, it can be customized a little more. I leave you a couple of links so you can see a little about both:
I also leave you the thread of another user to whom I responded on how to create a read-only user in case it helps:
Regards, Raúl.