Is that not the same access token?
To get access to the database an account is required. It is free to Sign-up for non-commercial use. Create an account and generate an access token. Once done, login to the VM with vm username and musicbrainz password.
By download initial data do you mean this?
Use an alternative PostgreSQL setup using mbslave that includes replication without the rest of MusicBrainz Server
If so it seems significantly more complicated than the rest of the VM setup, not sure if it's worth complicating the VM setup. Maybe you can give a bit more info as I am not seeing how it's meant o be setup exactly, at least not an a VM.