Unable to open Admin UI post installation of On prem instance in VB

I have followed the steps mentioned in the blog below for Onprem installation in Virtual Box

https://support.smartbear.com/swaggerhub/docs/enterprise/v1/installation/virtualbox.html

Hadn't faced any error during the installation and I can see the status of VM as 'running'.

Getting the error Resource Not found while accessing the link http://<hostname>:8000/ui/index.html

Tried NAT as well as Bridged Network config.