The device already has a password either I don't remember or I don't know, how do I erase it ?

Enter 25 characters in the setup field to erase the current password and click on the "Apply" button. Then you can create a new one of up to 24 characters.

If you cannot login because of the password, then there are two ways to reset the Barix device back to default settings:

A - the reset via hardware reset button
you have to reset the unit over the hardware reset button, in this case keep the reset button 10 seconds pressed.
This will reset ALL settings to factory defaults ! But the function of the hardware reset button can be disabled in some firmwares (e.g. in Streaming Client),
in this case reset via hardware reset button will not work. In such case only B will work.

B - serial firmware update
The serial rescue procedure cannot be disabled and will always work when the device is not defective. This updates the entire software on the device and reset all settings back to default settings.
Following is the link to instructions for the serial firmware update:
https://help.barix.com/knowledgebase/How-to-do-a-serial-firmware-update%3F.4555835800.html

Attention: when your Barix device is reachable via Internet, then we urgently recommend to set a strong password in the device setup !