Once you have successfully run the server, you can access the developer portal from your browser at <Server URL>/ui. For e.g if your Server Url is http://localhost:7777, frontend will be available at http://localhost:7777/ui.
Upon launching the Developer Portal, recall that we had set the API key in the server-config.tomlfile as part of the Docker. You will need to enter that API key here and click the Login button.