Great and very useful experiment, I followed your steps one by one but I have one question, as I saw that you accessed UDM as GUI throughout the browser, from where you have got the IP or domain name of this machine ??
Thanks Hassan. I am using a remote machine with a public address, and I didn't want to expose it in the article.
So, I edited my local hostfile so that it maps to my remote machine public IP address when I type "free5gc.example.com" in my browser :D
The domain "example.com" is not owned by anyone as it is reserved for testing and illustration purposes.