First go question

So… I feel like I have missed something simple as I cant find any topics on this. I have just installed and started up Home-Assistant OS on VirtualBox. It has started up and I now have a screen that says:

welcome to home assistant
homeassistant login:

When I try and enter homeassistant.local:8123 into a web browser it will not open anything.

Have I missed anything?

Background: I have loaded this on my son’s PC in VirtualBox, just to test it out before I buy a NUC. He has a pretty powerful PC and it is connected to our home network via Ethernet.

Well out of nowhere it just started working when I tried homeassistant:8123!

Normal. It takes ages for the first run to complete, alot of downloads.