htpasswd: cannot modify file /var/www/conf/arbitrage.passwd; use '-c' to create it

[pilubt]

Hi
I stopped installing here. I wanted to install under Ubuntu.
What is the correct format for this, or why do I get this error or how can I fix it?
htpasswd -b /var/www/conf/arbitrage.passwd username password
Error:
htpasswd: cannot modify file /var/www/conf/arbitrage.passwd; use '-c' to create it
If you could do it I would like to give you teamviewer access and of course I do not ask for free because I do not understand it.
My direct email: amunkaruha@gmail.com
Thanks

[yellowcandle]

for some reason, the -b flag doesn't work on ubuntu. I solved it by using:
htpasswd -n /var/www/conf/arbitrage.passwd [username]
and entering the password in the prompt New password: