Try this:

On your Rpi4-1, type "ip a" to find out its IP address.
For now I will assume it's
Then type "/usr/local/bin/indi-web -v"

This will start the indi web server

Then on your Rpi4-8 (or a laptop, or whatever), open a web browser
In the URL bar, type

The indi server web interface will come up in your browser
Configure your devices
Before you close the browser window, check the boxes at top left for "Auto Start" and "Auto Connect"

Then try rebooting Rpi4-1 without a monitor attached.

Again, try using the web server on Rpi4-1 in a browser on your laptop. Should pop right up.

Finally, go into Ekos on Rpi4-8 and configure your device profile to use the remote server