In case someone is struggling with /etc/hosts file.
I found this post.
The first reply is the key.
At least for me as I was trying to include the port number inside the hosts file.
incase you don’t want to update your /etc/hosts file
you can use this command
gobuster vhost -u http://$ip -w /usr/share/seclists/Discovery/DNS/subdomains-top1million-110000.txt -p ~/Desktop/pattern --exclude-length 301 -t 10
just make your own pattern file