There currently isn't a method for performing token based authentication

[desean1625]

Some servers require token based authentication prior to pulling data.

Currently kibana doesn't have a solution built into the maps package.

A potential solution is to update the maps package to allow sourced to make a request transform I describe a hacky half baked option in this thread
elastic/kibana#161292 (comment)

Creating a method in the kibana source to allow mapsources to register transform requests would allow us to perform authenitcation and set the appropriate headers
https://github.com/elastic/kibana/blob/main/x-pack/plugins/maps/public/connected_components/mb_map/transform_request.ts#L35