How to set up a printer in Ubuntu 18.04 LTS?

Question

linux

I installed it through printer devices, it appeared in CUPS, but it does not print test documents and others.
Drivers installed, connected to the printer.
Device URI: cups-brf:/
But on CUPS itself, it says:
Access denied
Enter your username and password or root credentials to access this page. If you are using Kerberos authentication, you must also have a valid Kerberos ticket.
Here's Ubuntu

Answer 1

You could at least take screenshots. Where, what, who asks what.
In general, cups itself hangs here 127.0.0.1:631

Answer 2

It is not certain that your printer is supported by cups.
I fully admit that on the manufacturer's website there is under Lin