Webpage Card or Dashboard using external network connection

Configuration
1

I am new to HA. please be kind…

My HA system is connected to my Home router via cable with static IP: 192.168.2.40 and to my Van (when it’s present) via wifi to vans Teltonika router with static IP: 192.168.10.108, so on two different subnet’s.
I have a Victron system setup in the van with a Cerbo GX, home page is 192.168.10.10

I have setup a HA Webpage dashboard with URL pointing to my van cerbo dashboard but it will not connect (time out error), but when the PC I am using to view home assistant connects to my van (wifi) everything works. This suggests that HA is using the network from my PC and not it’s own network connections, is this correct? is there something I am doing wrong?

So all works ok, but when I turn off my PC, home assistant can no longer show the van cerbo webpage? (everything is addressed by HTTP, no HTTPS)

2

Does #5 here help you at all?

I haven’t fixed the links on my website, sorry about that.

3

Many thanks. This looks like it might work, as you say the Custom Panel uses internal IP logic, unfortunately I am really new to HA and don’t know any Java so setting this up is beyond my scope currently. I really just wanted a webpage card that shows a webpage from an internal IP address.

I put this in my configuration.yaml…

panel_custom:
  - name: my-panel
    sidebar_title: Cerbo GX
    module_url: 'http://192.168.10.10/gui-v2'
    embed_iframe: true
    require_admin: true

but when I click on the Cerbo GX in the sidebar I get a blank screen showing “Unable to load the panel source: http://192.168.10.10/gui-v2.”