Can't set broker password

I’m installing Home Assistant first time, fresh on a Pi 5 with a Sonof Zigbee 3.0 USB dongle installed. I’m following a video on Youtube - sfsZF0R0HtE - and he installs the broker and says that no further set up is required. (I do the install and start it, along with the watchdog setting) I then find MQTT in the integrations but in the configuration it says “Password not set up”… and when I try to set a password, it says it can’t contact the broker.
That video does seem to be a different interface so maybe he did it on an older version?

Hello,

user name and password should probably set under MQTT Configure with the add-on not started yet, stop it and try to reconfigure and then restart it.

Alternatively the user you provided is not enable to login, just recheck user authorization in the same menu you created the user.