How to configure the command line for Redis password cracking without username

[loveshell]

Hello, I have a question about using Legba for Redis brute-force cracking. If I want to crack the password without a username, how should I configure the command line? What parameters do I need to specify to achieve password cracking only? Looking forward to your reply, thank you!

legba redis --target x.x.x.1-254 --password password.txt
legba v0.10.0

[INFO ] targets (254): x.x.x.1-254
[INFO ] username -> permutations (min:4 max:8 charset:abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_ !"#$%&'()*+,-./:;<=>?@[\]^`{|}~)
[INFO ] password -> wordlist /xxx/password.txt

username more more