Problems installing on Rapsbperry Pi 3+: root password missing

Hi there,
I fail to set up my first PirateBox on a Rapsbperry Pi 3+ following the installation-instructions on [piratebox.cc]. Everything works fine up to step 5 where the changing the password for root is required (first steps after flashing). I read in some post that changing the password for root is not possible via ssh, so I connected the Rapsbperry Pi directly to a keyboard and monitor. The result is just the same: the password for user root is not "root" as given in the instructions or it is not accepted. I can't even do a clean shutdown without being root. Any ideas?

Logged in as the alarm user you can do

sudo passwd

best regards

Matthias, thanks for the fast response!
"sudo passwd root" is exactly what I want to do following the instructions on >[piratebox.cc];:
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The default password for user root is root. It is strongly recommended to change this password as well. You can do this while being logged in as alarm running this command:
sudo passwd root
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But the password for root is required and "root" as a password is not accepted.

Wait.
The first password prompt should look like this:

$ sudo passwd root
[sudo] password for alarm:

So you need to provide the password for alarm user

Thanks, that solved my problem! I was able to set a new password for root now (without having to know the old one).