Not able to forward authentication from grafana to Elastic

Hello Guys, maybe you can help me, seems Grafana has a feature which enables to forward auth token for Elastic : Add authentication for data source plugins | Grafana Labs
I have been trying, seems that grafana sends an Autherization Bearer Token, but I am not able to authenticate. I also got this issue in github

@kevinurbinamoreira I saw your issue in github too, I’ve followed up with the dev team to see if they recall the details of the tests where they saw this work.