Need help regarding HTB Nexus (easy,linux) – issue regarding ffuf

I'm solving htb Nexus machine(easy,linux). There are two subdomains git,billing but on running ffuf it isn't returning anything.

I have used bitquark and top- million wordlists

I have attached screenshots can you please help me why ffuf not working?

i also tried using my custom wordlist containg words – git, billing still it not worked.

yes i can move to next step by reading the walkthrough but please someone explain me this ffuf issue and solution for it

Thank you