deploy blazor server to LAN

Question

I created a game, and I'm trying to play it with my friends. Since we don't want to pay any ASP.NET Core server space on Azure or whatsoever, we are running the game ourselves and trying to join using a VPN.

I created a Blazor app with an ASP.NET Core server. I modified the launchSettings.json like this:

"profiles": {
    "VikingBoardGames.Server": {
      "commandName": "Project",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "dotnetRunMessages": true,
      "inspectUri": "{wsProtocol}://{url.hostname}:{url.port}/_framework/debug/ws-proxy?browser={browserInspectUri}",
      "applicationUrl": "https://localhost:7141;http://localhost:5141;https://*:7141" <--- THIS !! 
    },
    [...]
}

Now, from my local computer where I have visual studio, I can access it via http:localhost:5141 AND http://MYIP:7141. which is good.

Then I created a VPN using hamachi. My friend joins the net. He can ping my hamachi IP.

I start the game on visual studio, and visit my IP to see it

He can visit my VPN IP on port 7141, where the page header gets loaded. Thethe "loading..." message appears, but it freezes.

Upon checking the developer tools on chrome on my friends' computer, I see:

DevTools failed to load source map: could not load content for chrome-extensions://gighmmpiobklfepjocnamgkkbiglidomm/browser-polufill.js.map: System error : net::ERR_FILE_NOT_FOUND

And at this point, I don't know how to proceed.

I don't need debugging facilities on his computer, just to be able to join the game and have fun.

What can we do?