Grafana about remote access

Hello everybody,

I would like to open Grafana with an VPN access with a web page. I use the product “eWon” and Talk2m.
I think, Talk2m do a reverse proxy to grafana, but i’m blocked to the login page and loading grafana.
I take you screenshoot for understand what it do.

I think is a configuration problem of grafana.

Thanks for your help !